Merge pull request #3 from eugenp/master

Sync with upstream

.gitignore

@@ -4,6 +4,7 @@ bin/
 *.class
 
 # Package Files #
+*.jar
 *.war
 *.ear
 
@@ -29,7 +30,7 @@ out/
 .DS_Store
 
 # Maven
-log/
+log/*
 target/
 
 # Gradle
@@ -82,4 +83,11 @@ jta/transaction-logs/
 software-security/sql-injection-samples/derby.log
 spring-soap/src/main/java/com/baeldung/springsoap/gen/
 /report-*.json
-transaction.log
+transaction.log
+*-shell.log
+
+apache-cxf/cxf-aegis/baeldung.xml
+apache-fop/src/test/resources/input.xml
+apache-fop/src/test/resources/output_herold.pdf
+apache-fop/src/test/resources/output_html2fo.pdf
+apache-fop/src/test/resources/output_jtidy.pdf

akka-http/README.md

@@ -1,3 +1,7 @@
-## Relevant articles:
+## Akka HTTP
+
+This module contains articles about Akka HTTP. 
+
+### Relevant articles:
 
 - [Introduction to Akka HTTP](https://www.baeldung.com/akka-http)

akka-streams/README.md

@@ -1,3 +1,7 @@
+## Akka Streams
+
+This module contains articles about Akka Streams. 
+
 ### Relevant articles
 
-- [Guide to Akka Streams](http://www.baeldung.com/akka-streams)
+- [Guide to Akka Streams](https://www.baeldung.com/akka-streams)

algorithms-genetic/README.md

@@ -1,6 +1,10 @@
-## Relevant articles:
+## Genetic Algorithms
 
-- [Introduction to Jenetics Library](http://www.baeldung.com/jenetics)
-- [Ant Colony Optimization](http://www.baeldung.com/java-ant-colony-optimization)
+This module contains articles about genetic algorithms. 
+
+### Relevant articles:
+
+- [Introduction to Jenetics Library](https://www.baeldung.com/jenetics)
+- [Ant Colony Optimization](https://www.baeldung.com/java-ant-colony-optimization)
 - [Design a Genetic Algorithm in Java](https://www.baeldung.com/java-genetic-algorithm)
 - [The Traveling Salesman Problem in Java](https://www.baeldung.com/java-simulated-annealing-for-traveling-salesman)

algorithms-miscellaneous-1/.gitignore

@@ -1,4 +0,0 @@
-/target/
-.settings/
-.classpath
-.project

algorithms-miscellaneous-1/README.md

@@ -1,18 +1,15 @@
-## Relevant articles:
+## Algorithms - Miscellaneous
 
-- [Validating Input With Finite Automata in Java](http://www.baeldung.com/java-finite-automata)
-- [Example of Hill Climbing Algorithm](http://www.baeldung.com/java-hill-climbing-algorithm)
-- [Monte Carlo Tree Search for Tic-Tac-Toe Game](http://www.baeldung.com/java-monte-carlo-tree-search)
-- [Binary Search Algorithm in Java](http://www.baeldung.com/java-binary-search)
-- [Introduction to Minimax Algorithm](http://www.baeldung.com/java-minimax-algorithm)
-- [How to Calculate Levenshtein Distance in Java?](http://www.baeldung.com/java-levenshtein-distance)
-- [How to Find the Kth Largest Element in Java](http://www.baeldung.com/java-kth-largest-element)
-- [Multi-Swarm Optimization Algorithm in Java](http://www.baeldung.com/java-multi-swarm-algorithm)
-- [String Search Algorithms for Large Texts](http://www.baeldung.com/java-full-text-search-algorithms)
-- [Check If a String Contains All The Letters of The Alphabet](https://www.baeldung.com/java-string-contains-all-letters)
-- [Find the Middle Element of a Linked List](http://www.baeldung.com/java-linked-list-middle-element)
-- [Calculate Factorial in Java](https://www.baeldung.com/java-calculate-factorial)
-- [Find Substrings That Are Palindromes in Java](https://www.baeldung.com/java-palindrome-substrings)
-- [Find the Longest Substring without Repeating Characters](https://www.baeldung.com/java-longest-substring-without-repeated-characters)
-- [Permutations of an Array in Java](https://www.baeldung.com/java-array-permutations)
-- [Generate Combinations in Java](https://www.baeldung.com/java-combinations-algorithm)
+This module contains articles about algorithms. Some classes of algorithms, e.g., [sorting](/../algorithms-sorting) and
+[genetic algorithms](/../algorithms-genetic), have their own dedicated modules. 
+
+### Relevant articles:
+
+- [Validating Input With Finite Automata in Java](https://www.baeldung.com/java-finite-automata)
+- [Example of Hill Climbing Algorithm](https://www.baeldung.com/java-hill-climbing-algorithm)
+- [Monte Carlo Tree Search for Tic-Tac-Toe Game](https://www.baeldung.com/java-monte-carlo-tree-search)
+- [Binary Search Algorithm in Java](https://www.baeldung.com/java-binary-search)
+- [Introduction to Minimax Algorithm](https://www.baeldung.com/java-minimax-algorithm)
+- [How to Calculate Levenshtein Distance in Java?](https://www.baeldung.com/java-levenshtein-distance)
+- [How to Find the Kth Largest Element in Java](https://www.baeldung.com/java-kth-largest-element)
+- More articles: [[next -->]](/../algorithms-miscellaneous-2)

algorithms-miscellaneous-2/.gitignore

@@ -1,4 +0,0 @@
-/target/
-.settings/
-.classpath
-.project

algorithms-miscellaneous-2/README.md

@@ -1,19 +1,16 @@
-## Relevant articles:
+## Algorithms - Miscellaneous
 
-- [Dijkstra Algorithm in Java](http://www.baeldung.com/java-dijkstra)
-- [Introduction to Cobertura](http://www.baeldung.com/cobertura)
-- [Test a Linked List for Cyclicity](http://www.baeldung.com/java-linked-list-cyclicity)
-- [Introduction to JGraphT](http://www.baeldung.com/jgrapht)
-- [A Maze Solver in Java](http://www.baeldung.com/java-solve-maze)
-- [Create a Sudoku Solver in Java](http://www.baeldung.com/java-sudoku)
-- [Displaying Money Amounts in Words](http://www.baeldung.com/java-money-into-words)
-- [A Collaborative Filtering Recommendation System in Java](http://www.baeldung.com/java-collaborative-filtering-recommendations)
-- [Check If Two Rectangles Overlap In Java](https://www.baeldung.com/java-check-if-two-rectangles-overlap)
-- [Calculate the Distance Between Two Points in Java](https://www.baeldung.com/java-distance-between-two-points)
-- [Find the Intersection of Two Lines in Java](https://www.baeldung.com/java-intersection-of-two-lines)
-- [Round Up to the Nearest Hundred](https://www.baeldung.com/java-round-up-nearest-hundred)
-- [Calculate Percentage in Java](https://www.baeldung.com/java-calculate-percentage)
-- [Converting Between Byte Arrays and Hexadecimal Strings in Java](https://www.baeldung.com/java-byte-arrays-hex-strings)
-- [Convert Latitude and Longitude to a 2D Point in Java](https://www.baeldung.com/java-convert-latitude-longitude)
-- [Reversing a Binary Tree in Java](https://www.baeldung.com/java-reversing-a-binary-tree)
-- [Find If Two Numbers Are Relatively Prime in Java](https://www.baeldung.com/java-two-relatively-prime-numbers)
+This module contains articles about algorithms. Some classes of algorithms, e.g., [sorting](/../algorithms-sorting) and
+[genetic algorithms](/../algorithms-genetic), have their own dedicated modules. 
+
+### Relevant articles:
+
+- [Dijkstra Shortest Path Algorithm in Java](https://www.baeldung.com/java-dijkstra)
+- [Introduction to Cobertura](https://www.baeldung.com/cobertura)
+- [Test a Linked List for Cyclicity](https://www.baeldung.com/java-linked-list-cyclicity)
+- [Introduction to JGraphT](https://www.baeldung.com/jgrapht)
+- [A Maze Solver in Java](https://www.baeldung.com/java-solve-maze)
+- [Create a Sudoku Solver in Java](https://www.baeldung.com/java-sudoku)
+- [Displaying Money Amounts in Words](https://www.baeldung.com/java-money-into-words)
+- [A Collaborative Filtering Recommendation System in Java](https://www.baeldung.com/java-collaborative-filtering-recommendations)
+- More articles: [[<-- prev]](/../algorithms-miscellaneous-1) [[next -->]](/../algorithms-miscellaneous-3)

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/Graph.java

@@ -0,0 +1,30 @@
+package com.baeldung.algorithms.astar;
+
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+
+public class Graph<T extends GraphNode> {
+    private final Set<T> nodes;
+
+    private final Map<String, Set<String>> connections;
+
+    public Graph(Set<T> nodes, Map<String, Set<String>> connections) {
+        this.nodes = nodes;
+        this.connections = connections;
+    }
+
+    public T getNode(String id) {
+        return nodes.stream()
+            .filter(node -> node.getId().equals(id))
+            .findFirst()
+            .orElseThrow(() -> new IllegalArgumentException("No node found with ID"));
+    }
+
+    public Set<T> getConnections(T node) {
+        return connections.get(node.getId()).stream()
+            .map(this::getNode)
+            .collect(Collectors.toSet());
+    }
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/GraphNode.java

@@ -0,0 +1,5 @@
+package com.baeldung.algorithms.astar;
+
+public interface GraphNode {
+    String getId();
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/RouteFinder.java

@@ -0,0 +1,66 @@
+package com.baeldung.algorithms.astar;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.PriorityQueue;
+import java.util.Queue;
+import java.util.stream.Collectors;
+
+public class RouteFinder<T extends GraphNode> {
+    private final Graph<T> graph;
+    private final Scorer<T> nextNodeScorer;
+    private final Scorer<T> targetScorer;
+
+    public RouteFinder(Graph<T> graph, Scorer<T> nextNodeScorer, Scorer<T> targetScorer) {
+        this.graph = graph;
+        this.nextNodeScorer = nextNodeScorer;
+        this.targetScorer = targetScorer;
+    }
+
+    public List<T> findRoute(T from, T to) {
+        Map<T, RouteNode<T>> allNodes = new HashMap<>();
+        Queue<RouteNode> openSet = new PriorityQueue<>();
+
+        RouteNode<T> start = new RouteNode<>(from, null, 0d, targetScorer.computeCost(from, to));
+        allNodes.put(from, start);
+        openSet.add(start);
+
+        while (!openSet.isEmpty()) {
+            System.out.println("Open Set contains: " + openSet.stream().map(RouteNode::getCurrent).collect(Collectors.toSet()));
+            RouteNode<T> next = openSet.poll();
+            System.out.println("Looking at node: " + next);
+            if (next.getCurrent().equals(to)) {
+                System.out.println("Found our destination!");
+
+                List<T> route = new ArrayList<>();
+                RouteNode<T> current = next;
+                do {
+                    route.add(0, current.getCurrent());
+                    current = allNodes.get(current.getPrevious());
+                } while (current != null);
+
+                System.out.println("Route: " + route);
+                return route;
+            }
+
+            graph.getConnections(next.getCurrent()).forEach(connection -> {
+                double newScore = next.getRouteScore() + nextNodeScorer.computeCost(next.getCurrent(), connection);
+                RouteNode<T> nextNode = allNodes.getOrDefault(connection, new RouteNode<>(connection));
+                allNodes.put(connection, nextNode);
+
+                if (nextNode.getRouteScore() > newScore) {
+                    nextNode.setPrevious(next.getCurrent());
+                    nextNode.setRouteScore(newScore);
+                    nextNode.setEstimatedScore(newScore + targetScorer.computeCost(connection, to));
+                    openSet.add(nextNode);
+                    System.out.println("Found a better route to node: " + nextNode);
+                }
+            });
+        }
+
+        throw new IllegalStateException("No route found");
+    }
+
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/RouteNode.java

@@ -0,0 +1,67 @@
+package com.baeldung.algorithms.astar;
+
+import java.util.StringJoiner;
+
+class RouteNode<T extends GraphNode> implements Comparable<RouteNode> {
+    private final T current;
+    private T previous;
+    private double routeScore;
+    private double estimatedScore;
+
+    RouteNode(T current) {
+        this(current, null, Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY);
+    }
+
+    RouteNode(T current, T previous, double routeScore, double estimatedScore) {
+        this.current = current;
+        this.previous = previous;
+        this.routeScore = routeScore;
+        this.estimatedScore = estimatedScore;
+    }
+
+    T getCurrent() {
+        return current;
+    }
+
+    T getPrevious() {
+        return previous;
+    }
+
+    double getRouteScore() {
+        return routeScore;
+    }
+
+    double getEstimatedScore() {
+        return estimatedScore;
+    }
+
+    void setPrevious(T previous) {
+        this.previous = previous;
+    }
+
+    void setRouteScore(double routeScore) {
+        this.routeScore = routeScore;
+    }
+
+    void setEstimatedScore(double estimatedScore) {
+        this.estimatedScore = estimatedScore;
+    }
+
+    @Override
+    public int compareTo(RouteNode other) {
+        if (this.estimatedScore > other.estimatedScore) {
+            return 1;
+        } else if (this.estimatedScore < other.estimatedScore) {
+            return -1;
+        } else {
+            return 0;
+        }
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", RouteNode.class.getSimpleName() + "[", "]").add("current=" + current)
+            .add("previous=" + previous).add("routeScore=" + routeScore).add("estimatedScore=" + estimatedScore)
+            .toString();
+    }
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/Scorer.java

@@ -0,0 +1,5 @@
+package com.baeldung.algorithms.astar;
+
+public interface Scorer<T extends GraphNode> {
+    double computeCost(T from, T to);
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/underground/HaversineScorer.java

@@ -0,0 +1,19 @@
+package com.baeldung.algorithms.astar.underground;
+
+import com.baeldung.algorithms.astar.Scorer;
+
+public class HaversineScorer implements Scorer<Station> {
+    @Override
+    public double computeCost(Station from, Station to) {
+        double R = 6372.8; // In kilometers
+
+        double dLat = Math.toRadians(to.getLatitude() - from.getLatitude());
+        double dLon = Math.toRadians(to.getLongitude() - from.getLongitude());
+        double lat1 = Math.toRadians(from.getLatitude());
+        double lat2 = Math.toRadians(to.getLatitude());
+
+        double a = Math.pow(Math.sin(dLat / 2),2) + Math.pow(Math.sin(dLon / 2),2) * Math.cos(lat1) * Math.cos(lat2);
+        double c = 2 * Math.asin(Math.sqrt(a));
+        return R * c;
+    }
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/underground/RouteFinderIntegrationTest.java

@@ -0,0 +1,643 @@
+package com.baeldung.algorithms.astar.underground;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import com.baeldung.algorithms.astar.Graph;
+import com.baeldung.algorithms.astar.RouteFinder;
+import org.junit.Before;
+import org.junit.Test;
+
+public class RouteFinderIntegrationTest {
+
+    private Graph<Station> underground;
+
+    private RouteFinder<Station> routeFinder;
+
+    @Before
+    public void setUp() throws Exception {
+        Set<Station> stations = new HashSet<>();
+        Map<String, Set<String>> connections = new HashMap<>();
+
+        stations.add(new Station("1", "Acton Town", 51.5028, -0.2801));
+        stations.add(new Station("2", "Aldgate", 51.5143, -0.0755));
+        stations.add(new Station("3", "Aldgate East", 51.5154, -0.0726));
+        stations.add(new Station("4", "All Saints", 51.5107, -0.013));
+        stations.add(new Station("5", "Alperton", 51.5407, -0.2997));
+        stations.add(new Station("6", "Amersham", 51.6736, -0.607));
+        stations.add(new Station("7", "Angel", 51.5322, -0.1058));
+        stations.add(new Station("8", "Archway", 51.5653, -0.1353));
+        stations.add(new Station("9", "Arnos Grove", 51.6164, -0.1331));
+        stations.add(new Station("10", "Arsenal", 51.5586, -0.1059));
+        stations.add(new Station("11", "Baker Street", 51.5226, -0.1571));
+        stations.add(new Station("12", "Balham", 51.4431, -0.1525));
+        stations.add(new Station("13", "Bank", 51.5133, -0.0886));
+        stations.add(new Station("14", "Barbican", 51.5204, -0.0979));
+        stations.add(new Station("15", "Barking", 51.5396, 0.081));
+        stations.add(new Station("16", "Barkingside", 51.5856, 0.0887));
+        stations.add(new Station("17", "Barons Court", 51.4905, -0.2139));
+        stations.add(new Station("18", "Bayswater", 51.5121, -0.1879));
+        stations.add(new Station("19", "Beckton", 51.5148, 0.0613));
+        stations.add(new Station("20", "Beckton Park", 51.5087, 0.055));
+        stations.add(new Station("21", "Becontree", 51.5403, 0.127));
+        stations.add(new Station("22", "Belsize Park", 51.5504, -0.1642));
+        stations.add(new Station("23", "Bermondsey", 51.4979, -0.0637));
+        stations.add(new Station("24", "Bethnal Green", 51.527, -0.0549));
+        stations.add(new Station("25", "Blackfriars", 51.512, -0.1031));
+        stations.add(new Station("26", "Blackhorse Road", 51.5867, -0.0417));
+        stations.add(new Station("27", "Blackwall", 51.5079, -0.0066));
+        stations.add(new Station("28", "Bond Street", 51.5142, -0.1494));
+        stations.add(new Station("29", "Borough", 51.5011, -0.0943));
+        stations.add(new Station("30", "Boston Manor", 51.4956, -0.325));
+        stations.add(new Station("31", "Bounds Green", 51.6071, -0.1243));
+        stations.add(new Station("32", "Bow Church", 51.5273, -0.0208));
+        stations.add(new Station("33", "Bow Road", 51.5269, -0.0247));
+        stations.add(new Station("34", "Brent Cross", 51.5766, -0.2136));
+        stations.add(new Station("35", "Brixton", 51.4627, -0.1145));
+        stations.add(new Station("36", "Bromley-By-Bow", 51.5248, -0.0119));
+        stations.add(new Station("37", "Buckhurst Hill", 51.6266, 0.0471));
+        stations.add(new Station("38", "Burnt Oak", 51.6028, -0.2641));
+        stations.add(new Station("39", "Caledonian Road", 51.5481, -0.1188));
+        stations.add(new Station("40", "Camden Town", 51.5392, -0.1426));
+        stations.add(new Station("41", "Canada Water", 51.4982, -0.0502));
+        stations.add(new Station("42", "Canary Wharf", 51.5051, -0.0209));
+        stations.add(new Station("43", "Canning Town", 51.5147, 0.0082));
+        stations.add(new Station("44", "Cannon Street", 51.5113, -0.0904));
+        stations.add(new Station("45", "Canons Park", 51.6078, -0.2947));
+        stations.add(new Station("46", "Chalfont & Latimer", 51.6679, -0.561));
+        stations.add(new Station("47", "Chalk Farm", 51.5441, -0.1538));
+        stations.add(new Station("48", "Chancery Lane", 51.5185, -0.1111));
+        stations.add(new Station("49", "Charing Cross", 51.508, -0.1247));
+        stations.add(new Station("50", "Chesham", 51.7052, -0.611));
+        stations.add(new Station("51", "Chigwell", 51.6177, 0.0755));
+        stations.add(new Station("52", "Chiswick Park", 51.4946, -0.2678));
+        stations.add(new Station("53", "Chorleywood", 51.6543, -0.5183));
+        stations.add(new Station("54", "Clapham Common", 51.4618, -0.1384));
+        stations.add(new Station("55", "Clapham North", 51.4649, -0.1299));
+        stations.add(new Station("56", "Clapham South", 51.4527, -0.148));
+        stations.add(new Station("57", "Cockfosters", 51.6517, -0.1496));
+        stations.add(new Station("58", "Colindale", 51.5955, -0.2502));
+        stations.add(new Station("59", "Colliers Wood", 51.418, -0.1778));
+        stations.add(new Station("60", "Covent Garden", 51.5129, -0.1243));
+        stations.add(new Station("61", "Crossharbour & London Arena", 51.4957, -0.0144));
+        stations.add(new Station("62", "Croxley", 51.647, -0.4412));
+        stations.add(new Station("63", "Custom House", 51.5095, 0.0276));
+        stations.add(new Station("64", "Cutty Sark", 51.4827, -0.0096));
+        stations.add(new Station("65", "Cyprus", 51.5085, 0.064));
+        stations.add(new Station("66", "Dagenham East", 51.5443, 0.1655));
+        stations.add(new Station("67", "Dagenham Heathway", 51.5417, 0.1469));
+        stations.add(new Station("68", "Debden", 51.6455, 0.0838));
+        stations.add(new Station("69", "Deptford Bridge", 51.474, -0.0216));
+        stations.add(new Station("70", "Devons Road", 51.5223, -0.0173));
+        stations.add(new Station("71", "Dollis Hill", 51.552, -0.2387));
+        stations.add(new Station("72", "Ealing Broadway", 51.5152, -0.3017));
+        stations.add(new Station("73", "Ealing Common", 51.5101, -0.2882));
+        stations.add(new Station("74", "Earl's Court", 51.492, -0.1973));
+        stations.add(new Station("75", "Eastcote", 51.5765, -0.397));
+        stations.add(new Station("76", "East Acton", 51.5168, -0.2474));
+        stations.add(new Station("77", "East Finchley", 51.5874, -0.165));
+        stations.add(new Station("78", "East Ham", 51.5394, 0.0518));
+        stations.add(new Station("79", "East India", 51.5093, -0.0021));
+        stations.add(new Station("80", "East Putney", 51.4586, -0.2112));
+        stations.add(new Station("81", "Edgware", 51.6137, -0.275));
+        stations.add(new Station("82", "Edgware Road (B)", 51.5199, -0.1679));
+        stations.add(new Station("83", "Edgware Road (C)", 51.5203, -0.17));
+        stations.add(new Station("84", "Elephant & Castle", 51.4943, -0.1001));
+        stations.add(new Station("85", "Elm Park", 51.5496, 0.1977));
+        stations.add(new Station("86", "Elverson Road", 51.4693, -0.0174));
+        stations.add(new Station("87", "Embankment", 51.5074, -0.1223));
+        stations.add(new Station("88", "Epping", 51.6937, 0.1139));
+        stations.add(new Station("89", "Euston", 51.5282, -0.1337));
+        stations.add(new Station("90", "Euston Square", 51.526, -0.1359));
+        stations.add(new Station("91", "Fairlop", 51.596, 0.0912));
+        stations.add(new Station("92", "Farringdon", 51.5203, -0.1053));
+        stations.add(new Station("93", "Finchley Central", 51.6012, -0.1932));
+        stations.add(new Station("94", "Finchley Road", 51.5472, -0.1803));
+        stations.add(new Station("95", "Finsbury Park", 51.5642, -0.1065));
+        stations.add(new Station("96", "Fulham Broadway", 51.4804, -0.195));
+        stations.add(new Station("97", "Gallions Reach", 51.5096, 0.0716));
+        stations.add(new Station("98", "Gants Hill", 51.5765, 0.0663));
+        stations.add(new Station("99", "Gloucester Road", 51.4945, -0.1829));
+        stations.add(new Station("100", "Golders Green", 51.5724, -0.1941));
+        stations.add(new Station("101", "Goldhawk Road", 51.5018, -0.2267));
+        stations.add(new Station("102", "Goodge Street", 51.5205, -0.1347));
+        stations.add(new Station("103", "Grange Hill", 51.6132, 0.0923));
+        stations.add(new Station("104", "Great Portland Street", 51.5238, -0.1439));
+        stations.add(new Station("105", "Greenford", 51.5423, -0.3456));
+        stations.add(new Station("106", "Greenwich", 51.4781, -0.0149));
+        stations.add(new Station("107", "Green Park", 51.5067, -0.1428));
+        stations.add(new Station("108", "Gunnersbury", 51.4915, -0.2754));
+        stations.add(new Station("109", "Hainault", 51.603, 0.0933));
+        stations.add(new Station("110", "Hammersmith", 51.4936, -0.2251));
+        stations.add(new Station("111", "Hampstead", 51.5568, -0.178));
+        stations.add(new Station("112", "Hanger Lane", 51.5302, -0.2933));
+        stations.add(new Station("113", "Harlesden", 51.5362, -0.2575));
+        stations.add(new Station("114", "Harrow & Wealdston", 51.5925, -0.3351));
+        stations.add(new Station("115", "Harrow-on-the-Hill", 51.5793, -0.3366));
+        stations.add(new Station("116", "Hatton Cross", 51.4669, -0.4227));
+        stations.add(new Station("117", "Heathrow Terminals 1, 2 & 3", 51.4713, -0.4524));
+        stations.add(new Station("118", "Heathrow Terminal 4", 51.4598, -0.4476));
+        stations.add(new Station("119", "Hendon Central", 51.5829, -0.2259));
+        stations.add(new Station("120", "Heron Quays", 51.5033, -0.0215));
+        stations.add(new Station("121", "High Barnet", 51.6503, -0.1943));
+        stations.add(new Station("122", "High Street Kensington", 51.5009, -0.1925));
+        stations.add(new Station("123", "Highbury & Islington", 51.546, -0.104));
+        stations.add(new Station("124", "Highgate", 51.5777, -0.1458));
+        stations.add(new Station("125", "Hillingdon", 51.5538, -0.4499));
+        stations.add(new Station("126", "Holborn", 51.5174, -0.12));
+        stations.add(new Station("127", "Holland Park", 51.5075, -0.206));
+        stations.add(new Station("128", "Holloway Road", 51.5526, -0.1132));
+        stations.add(new Station("129", "Hornchurch", 51.5539, 0.2184));
+        stations.add(new Station("130", "Hounslow Central", 51.4713, -0.3665));
+        stations.add(new Station("131", "Hounslow East", 51.4733, -0.3564));
+        stations.add(new Station("132", "Hounslow West", 51.4734, -0.3855));
+        stations.add(new Station("133", "Hyde Park Corner", 51.5027, -0.1527));
+        stations.add(new Station("134", "Ickenham", 51.5619, -0.4421));
+        stations.add(new Station("135", "Island Gardens", 51.4871, -0.0101));
+        stations.add(new Station("136", "Kennington", 51.4884, -0.1053));
+        stations.add(new Station("137", "Kensal Green", 51.5304, -0.225));
+        stations.add(new Station("138", "Kensington (Olympia)", 51.4983, -0.2106));
+        stations.add(new Station("139", "Kentish Town", 51.5507, -0.1402));
+        stations.add(new Station("140", "Kenton", 51.5816, -0.3162));
+        stations.add(new Station("141", "Kew Gardens", 51.477, -0.285));
+        stations.add(new Station("142", "Kilburn", 51.5471, -0.2047));
+        stations.add(new Station("143", "Kilburn Park", 51.5351, -0.1939));
+        stations.add(new Station("144", "Kingsbury", 51.5846, -0.2786));
+        stations.add(new Station("145", "King's Cross St. Pancras", 51.5308, -0.1238));
+        stations.add(new Station("146", "Knightsbridge", 51.5015, -0.1607));
+        stations.add(new Station("147", "Ladbroke Grove", 51.5172, -0.2107));
+        stations.add(new Station("148", "Lambeth North", 51.4991, -0.1115));
+        stations.add(new Station("149", "Lancaster Gate", 51.5119, -0.1756));
+        stations.add(new Station("150", "Latimer Road", 51.5139, -0.2172));
+        stations.add(new Station("151", "Leicester Square", 51.5113, -0.1281));
+        stations.add(new Station("152", "Lewisham", 51.4657, -0.0142));
+        stations.add(new Station("153", "Leyton", 51.5566, -0.0053));
+        stations.add(new Station("154", "Leytonstone", 51.5683, 0.0083));
+        stations.add(new Station("155", "Limehouse", 51.5123, -0.0396));
+        stations.add(new Station("156", "Liverpool Street", 51.5178, -0.0823));
+        stations.add(new Station("157", "London Bridge", 51.5052, -0.0864));
+        stations.add(new Station("158", "Loughton", 51.6412, 0.0558));
+        stations.add(new Station("159", "Maida Vale", 51.53, -0.1854));
+        stations.add(new Station("160", "Manor House", 51.5712, -0.0958));
+        stations.add(new Station("161", "Mansion House", 51.5122, -0.094));
+        stations.add(new Station("162", "Marble Arch", 51.5136, -0.1586));
+        stations.add(new Station("163", "Marylebone", 51.5225, -0.1631));
+        stations.add(new Station("164", "Mile End", 51.5249, -0.0332));
+        stations.add(new Station("165", "Mill Hill East", 51.6082, -0.2103));
+        stations.add(new Station("166", "Monument", 51.5108, -0.0863));
+        stations.add(new Station("167", "Moorgate", 51.5186, -0.0886));
+        stations.add(new Station("168", "Moor Park", 51.6294, -0.432));
+        stations.add(new Station("169", "Morden", 51.4022, -0.1948));
+        stations.add(new Station("170", "Mornington Crescent", 51.5342, -0.1387));
+        stations.add(new Station("171", "Mudchute", 51.4902, -0.0145));
+        stations.add(new Station("172", "Neasden", 51.5542, -0.2503));
+        stations.add(new Station("173", "Newbury Park", 51.5756, 0.0899));
+        stations.add(new Station("174", "New Cross", 51.4767, -0.0327));
+        stations.add(new Station("175", "New Cross Gate", 51.4757, -0.0402));
+        stations.add(new Station("176", "Northfields", 51.4995, -0.3142));
+        stations.add(new Station("177", "Northolt", 51.5483, -0.3687));
+        stations.add(new Station("178", "Northwick Park", 51.5784, -0.3184));
+        stations.add(new Station("179", "Northwood", 51.6111, -0.424));
+        stations.add(new Station("180", "Northwood Hills", 51.6004, -0.4092));
+        stations.add(new Station("181", "North Acton", 51.5237, -0.2597));
+        stations.add(new Station("182", "North Ealing", 51.5175, -0.2887));
+        stations.add(new Station("183", "North Greenwich", 51.5005, 0.0039));
+        stations.add(new Station("184", "North Harrow", 51.5846, -0.3626));
+        stations.add(new Station("185", "North Wembley", 51.5621, -0.3034));
+        stations.add(new Station("186", "Notting Hill Gate", 51.5094, -0.1967));
+        stations.add(new Station("187", "Oakwood", 51.6476, -0.1318));
+        stations.add(new Station("188", "Old Street", 51.5263, -0.0873));
+        stations.add(new Station("189", "Osterley", 51.4813, -0.3522));
+        stations.add(new Station("190", "Oval", 51.4819, -0.113));
+        stations.add(new Station("191", "Oxford Circus", 51.515, -0.1415));
+        stations.add(new Station("192", "Paddington", 51.5154, -0.1755));
+        stations.add(new Station("193", "Park Royal", 51.527, -0.2841));
+        stations.add(new Station("194", "Parsons Green", 51.4753, -0.2011));
+        stations.add(new Station("195", "Perivale", 51.5366, -0.3232));
+        stations.add(new Station("196", "Picadilly Circus", 51.5098, -0.1342));
+        stations.add(new Station("197", "Pimlico", 51.4893, -0.1334));
+        stations.add(new Station("198", "Pinner", 51.5926, -0.3805));
+        stations.add(new Station("199", "Plaistow", 51.5313, 0.0172));
+        stations.add(new Station("200", "Poplar", 51.5077, -0.0173));
+        stations.add(new Station("201", "Preston Road", 51.572, -0.2954));
+        stations.add(new Station("202", "Prince Regent", 51.5093, 0.0336));
+        stations.add(new Station("203", "Pudding Mill Lane", 51.5343, -0.0139));
+        stations.add(new Station("204", "Putney Bridge", 51.4682, -0.2089));
+        stations.add(new Station("205", "Queen's Park", 51.5341, -0.2047));
+        stations.add(new Station("206", "Queensbury", 51.5942, -0.2861));
+        stations.add(new Station("207", "Queensway", 51.5107, -0.1877));
+        stations.add(new Station("208", "Ravenscourt Park", 51.4942, -0.2359));
+        stations.add(new Station("209", "Rayners Lane", 51.5753, -0.3714));
+        stations.add(new Station("210", "Redbridge", 51.5763, 0.0454));
+        stations.add(new Station("211", "Regent's Park", 51.5234, -0.1466));
+        stations.add(new Station("212", "Richmond", 51.4633, -0.3013));
+        stations.add(new Station("213", "Rickmansworth", 51.6404, -0.4733));
+        stations.add(new Station("214", "Roding Valley", 51.6171, 0.0439));
+        stations.add(new Station("215", "Rotherhithe", 51.501, -0.0525));
+        stations.add(new Station("216", "Royal Albert", 51.5084, 0.0465));
+        stations.add(new Station("217", "Royal Oak", 51.519, -0.188));
+        stations.add(new Station("218", "Royal Victoria", 51.5091, 0.0181));
+        stations.add(new Station("219", "Ruislip", 51.5715, -0.4213));
+        stations.add(new Station("220", "Ruislip Gardens", 51.5606, -0.4103));
+        stations.add(new Station("221", "Ruislip Manor", 51.5732, -0.4125));
+        stations.add(new Station("222", "Russell Square", 51.523, -0.1244));
+        stations.add(new Station("223", "Seven Sisters", 51.5822, -0.0749));
+        stations.add(new Station("224", "Shadwell", 51.5117, -0.056));
+        stations.add(new Station("225", "Shepherd's Bush (C)", 51.5046, -0.2187));
+        stations.add(new Station("226", "Shepherd's Bush (H)", 51.5058, -0.2265));
+        stations.add(new Station("227", "Shoreditch", 51.5227, -0.0708));
+        stations.add(new Station("228", "Sloane Square", 51.4924, -0.1565));
+        stations.add(new Station("229", "Snaresbrook", 51.5808, 0.0216));
+        stations.add(new Station("230", "Southfields", 51.4454, -0.2066));
+        stations.add(new Station("231", "Southgate", 51.6322, -0.128));
+        stations.add(new Station("232", "Southwark", 51.501, -0.1052));
+        stations.add(new Station("233", "South Ealing", 51.5011, -0.3072));
+        stations.add(new Station("234", "South Harrow", 51.5646, -0.3521));
+        stations.add(new Station("235", "South Kensington", 51.4941, -0.1738));
+        stations.add(new Station("236", "South Kenton", 51.5701, -0.3081));
+        stations.add(new Station("237", "South Quay", 51.5007, -0.0191));
+        stations.add(new Station("238", "South Ruislip", 51.5569, -0.3988));
+        stations.add(new Station("239", "South Wimbledon", 51.4154, -0.1919));
+        stations.add(new Station("240", "South Woodford", 51.5917, 0.0275));
+        stations.add(new Station("241", "Stamford Brook", 51.495, -0.2459));
+        stations.add(new Station("242", "Stanmore", 51.6194, -0.3028));
+        stations.add(new Station("243", "Stepney Green", 51.5221, -0.047));
+        stations.add(new Station("244", "Stockwell", 51.4723, -0.123));
+        stations.add(new Station("245", "Stonebridge Park", 51.5439, -0.2759));
+        stations.add(new Station("246", "Stratford", 51.5416, -0.0042));
+        stations.add(new Station("247", "St. James's Park", 51.4994, -0.1335));
+        stations.add(new Station("248", "St. John's Wood", 51.5347, -0.174));
+        stations.add(new Station("249", "St. Paul's", 51.5146, -0.0973));
+        stations.add(new Station("250", "Sudbury Hill", 51.5569, -0.3366));
+        stations.add(new Station("251", "Sudbury Town", 51.5507, -0.3156));
+        stations.add(new Station("252", "Surrey Quays", 51.4933, -0.0478));
+        stations.add(new Station("253", "Swiss Cottage", 51.5432, -0.1738));
+        stations.add(new Station("254", "Temple", 51.5111, -0.1141));
+        stations.add(new Station("255", "Theydon Bois", 51.6717, 0.1033));
+        stations.add(new Station("256", "Tooting Bec", 51.4361, -0.1598));
+        stations.add(new Station("257", "Tooting Broadway", 51.4275, -0.168));
+        stations.add(new Station("258", "Tottenham Court Road", 51.5165, -0.131));
+        stations.add(new Station("259", "Tottenham Hale", 51.5882, -0.0594));
+        stations.add(new Station("260", "Totteridge & Whetstone", 51.6302, -0.1791));
+        stations.add(new Station("261", "Tower Gateway", 51.5106, -0.0743));
+        stations.add(new Station("262", "Tower Hill", 51.5098, -0.0766));
+        stations.add(new Station("263", "Tufnell Park", 51.5567, -0.1374));
+        stations.add(new Station("264", "Turnham Green", 51.4951, -0.2547));
+        stations.add(new Station("265", "Turnpike Lane", 51.5904, -0.1028));
+        stations.add(new Station("266", "Upminster", 51.559, 0.251));
+        stations.add(new Station("267", "Upminster Bridge", 51.5582, 0.2343));
+        stations.add(new Station("268", "Upney", 51.5385, 0.1014));
+        stations.add(new Station("269", "Upton Park", 51.5352, 0.0343));
+        stations.add(new Station("270", "Uxbridge", 51.5463, -0.4786));
+        stations.add(new Station("271", "Vauxhall", 51.4861, -0.1253));
+        stations.add(new Station("272", "Victoria", 51.4965, -0.1447));
+        stations.add(new Station("273", "Walthamstow Central", 51.583, -0.0195));
+        stations.add(new Station("274", "Wanstead", 51.5775, 0.0288));
+        stations.add(new Station("275", "Wapping", 51.5043, -0.0558));
+        stations.add(new Station("276", "Warren Street", 51.5247, -0.1384));
+        stations.add(new Station("277", "Warwick Avenue", 51.5235, -0.1835));
+        stations.add(new Station("278", "Waterloo", 51.5036, -0.1143));
+        stations.add(new Station("279", "Watford", 51.6573, -0.4177));
+        stations.add(new Station("280", "Wembley Central", 51.5519, -0.2963));
+        stations.add(new Station("281", "Wembley Park", 51.5635, -0.2795));
+        stations.add(new Station("282", "Westbourne Park", 51.521, -0.2011));
+        stations.add(new Station("283", "Westferry", 51.5097, -0.0265));
+        stations.add(new Station("284", "Westminster", 51.501, -0.1254));
+        stations.add(new Station("285", "West Acton", 51.518, -0.2809));
+        stations.add(new Station("286", "West Brompton", 51.4872, -0.1953));
+        stations.add(new Station("287", "West Finchley", 51.6095, -0.1883));
+        stations.add(new Station("288", "West Ham", 51.5287, 0.0056));
+        stations.add(new Station("289", "West Hampstead", 51.5469, -0.1906));
+        stations.add(new Station("290", "West Harrow", 51.5795, -0.3533));
+        stations.add(new Station("291", "West India Quay", 51.507, -0.0203));
+        stations.add(new Station("292", "West Kensington", 51.4907, -0.2065));
+        stations.add(new Station("293", "West Ruislip", 51.5696, -0.4376));
+        stations.add(new Station("294", "Whitechapel", 51.5194, -0.0612));
+        stations.add(new Station("295", "White City", 51.512, -0.2239));
+        stations.add(new Station("296", "Willesden Green", 51.5492, -0.2215));
+        stations.add(new Station("297", "Willesden Junction", 51.5326, -0.2478));
+        stations.add(new Station("298", "Wimbledon", 51.4214, -0.2064));
+        stations.add(new Station("299", "Wimbledon Park", 51.4343, -0.1992));
+        stations.add(new Station("300", "Woodford", 51.607, 0.0341));
+        stations.add(new Station("301", "Woodside Park", 51.6179, -0.1856));
+        stations.add(new Station("302", "Wood Green", 51.5975, -0.1097));
+
+        connections.put("1", Stream.of("52","73","73","233","264").collect(Collectors.toSet()));
+        connections.put("2", Stream.of("156","262","156").collect(Collectors.toSet()));
+        connections.put("3", Stream.of("262","294","156","294").collect(Collectors.toSet()));
+        connections.put("4", Stream.of("70","200").collect(Collectors.toSet()));
+        connections.put("5", Stream.of("193","251").collect(Collectors.toSet()));
+        connections.put("6", Stream.of("46").collect(Collectors.toSet()));
+        connections.put("7", Stream.of("145","188").collect(Collectors.toSet()));
+        connections.put("8", Stream.of("124","263").collect(Collectors.toSet()));
+        connections.put("9", Stream.of("31","231").collect(Collectors.toSet()));
+        connections.put("10", Stream.of("95","128").collect(Collectors.toSet()));
+        connections.put("11", Stream.of("163","211","83","104","83","104","28","248","94","104").collect(Collectors.toSet()));
+        connections.put("12", Stream.of("56","256").collect(Collectors.toSet()));
+        connections.put("13", Stream.of("156","249","224","157","167","278").collect(Collectors.toSet()));
+        connections.put("14", Stream.of("92","167","92","167","92","167").collect(Collectors.toSet()));
+        connections.put("15", Stream.of("78","268","78").collect(Collectors.toSet()));
+        connections.put("16", Stream.of("91","173").collect(Collectors.toSet()));
+        connections.put("17", Stream.of("110","292","74","110").collect(Collectors.toSet()));
+        connections.put("18", Stream.of("186","192","186","192").collect(Collectors.toSet()));
+        connections.put("19", Stream.of("97").collect(Collectors.toSet()));
+        connections.put("20", Stream.of("65","216").collect(Collectors.toSet()));
+        connections.put("21", Stream.of("67","268").collect(Collectors.toSet()));
+        connections.put("22", Stream.of("47","111").collect(Collectors.toSet()));
+        connections.put("23", Stream.of("41","157").collect(Collectors.toSet()));
+        connections.put("24", Stream.of("156","164").collect(Collectors.toSet()));
+        connections.put("25", Stream.of("161","254","161","254").collect(Collectors.toSet()));
+        connections.put("26", Stream.of("259","273").collect(Collectors.toSet()));
+        connections.put("27", Stream.of("79","200").collect(Collectors.toSet()));
+        connections.put("28", Stream.of("162","191","11","107").collect(Collectors.toSet()));
+        connections.put("29", Stream.of("84","157").collect(Collectors.toSet()));
+        connections.put("30", Stream.of("176","189").collect(Collectors.toSet()));
+        connections.put("31", Stream.of("9","302").collect(Collectors.toSet()));
+        connections.put("32", Stream.of("70","203").collect(Collectors.toSet()));
+        connections.put("33", Stream.of("36","164","36","164").collect(Collectors.toSet()));
+        connections.put("34", Stream.of("100","119").collect(Collectors.toSet()));
+        connections.put("35", Stream.of("244").collect(Collectors.toSet()));
+        connections.put("36", Stream.of("33","288","33","288").collect(Collectors.toSet()));
+        connections.put("37", Stream.of("158","300").collect(Collectors.toSet()));
+        connections.put("38", Stream.of("58","81").collect(Collectors.toSet()));
+        connections.put("39", Stream.of("128","145").collect(Collectors.toSet()));
+        connections.put("40", Stream.of("47","89","139","170").collect(Collectors.toSet()));
+        connections.put("41", Stream.of("215","252","23","42").collect(Collectors.toSet()));
+        connections.put("42", Stream.of("120","291","41","183").collect(Collectors.toSet()));
+        connections.put("43", Stream.of("79","218","183","288").collect(Collectors.toSet()));
+        connections.put("44", Stream.of("161","166","161","166").collect(Collectors.toSet()));
+        connections.put("45", Stream.of("206","242").collect(Collectors.toSet()));
+        connections.put("46", Stream.of("6","50","53").collect(Collectors.toSet()));
+        connections.put("47", Stream.of("22","40").collect(Collectors.toSet()));
+        connections.put("48", Stream.of("126","249").collect(Collectors.toSet()));
+        connections.put("49", Stream.of("87","196","87","151").collect(Collectors.toSet()));
+        connections.put("50", Stream.of("46").collect(Collectors.toSet()));
+        connections.put("51", Stream.of("103","214").collect(Collectors.toSet()));
+        connections.put("52", Stream.of("1","264").collect(Collectors.toSet()));
+        connections.put("53", Stream.of("46","213").collect(Collectors.toSet()));
+        connections.put("54", Stream.of("55","56").collect(Collectors.toSet()));
+        connections.put("55", Stream.of("54","244").collect(Collectors.toSet()));
+        connections.put("56", Stream.of("12","54").collect(Collectors.toSet()));
+        connections.put("57", Stream.of("187").collect(Collectors.toSet()));
+        connections.put("58", Stream.of("38","119").collect(Collectors.toSet()));
+        connections.put("59", Stream.of("239","257").collect(Collectors.toSet()));
+        connections.put("60", Stream.of("126","151").collect(Collectors.toSet()));
+        connections.put("61", Stream.of("171","237").collect(Collectors.toSet()));
+        connections.put("62", Stream.of("168","279").collect(Collectors.toSet()));
+        connections.put("63", Stream.of("202","218").collect(Collectors.toSet()));
+        connections.put("64", Stream.of("106","135").collect(Collectors.toSet()));
+        connections.put("65", Stream.of("20","97").collect(Collectors.toSet()));
+        connections.put("66", Stream.of("67","85").collect(Collectors.toSet()));
+        connections.put("67", Stream.of("21","66").collect(Collectors.toSet()));
+        connections.put("68", Stream.of("158","255").collect(Collectors.toSet()));
+        connections.put("69", Stream.of("86","106").collect(Collectors.toSet()));
+        connections.put("70", Stream.of("4","32").collect(Collectors.toSet()));
+        connections.put("71", Stream.of("172","296").collect(Collectors.toSet()));
+        connections.put("72", Stream.of("285","73").collect(Collectors.toSet()));
+        connections.put("73", Stream.of("72","1","1","182").collect(Collectors.toSet()));
+        connections.put("74", Stream.of("99","122","138","286","292","17","99").collect(Collectors.toSet()));
+        connections.put("75", Stream.of("209","221","209","221").collect(Collectors.toSet()));
+        connections.put("76", Stream.of("181","295").collect(Collectors.toSet()));
+        connections.put("77", Stream.of("93","124").collect(Collectors.toSet()));
+        connections.put("78", Stream.of("15","269","15","269").collect(Collectors.toSet()));
+        connections.put("79", Stream.of("27","43").collect(Collectors.toSet()));
+        connections.put("80", Stream.of("204","230").collect(Collectors.toSet()));
+        connections.put("81", Stream.of("38").collect(Collectors.toSet()));
+        connections.put("82", Stream.of("163","192").collect(Collectors.toSet()));
+        connections.put("83", Stream.of("11","192","192","11","192").collect(Collectors.toSet()));
+        connections.put("84", Stream.of("148","29","136").collect(Collectors.toSet()));
+        connections.put("85", Stream.of("66","129").collect(Collectors.toSet()));
+        connections.put("86", Stream.of("69","152").collect(Collectors.toSet()));
+        connections.put("87", Stream.of("49","278","254","284","254","284","49","278").collect(Collectors.toSet()));
+        connections.put("88", Stream.of("255").collect(Collectors.toSet()));
+        connections.put("89", Stream.of("40","145","170","276","145","276").collect(Collectors.toSet()));
+        connections.put("90", Stream.of("104","145","104","145","104","145").collect(Collectors.toSet()));
+        connections.put("91", Stream.of("16","109").collect(Collectors.toSet()));
+        connections.put("92", Stream.of("14","145","14","145","14","145").collect(Collectors.toSet()));
+        connections.put("93", Stream.of("77","165","287").collect(Collectors.toSet()));
+        connections.put("94", Stream.of("253","289","11","281").collect(Collectors.toSet()));
+        connections.put("95", Stream.of("10","160","123","223").collect(Collectors.toSet()));
+        connections.put("96", Stream.of("194","286").collect(Collectors.toSet()));
+        connections.put("97", Stream.of("19","65").collect(Collectors.toSet()));
+        connections.put("98", Stream.of("173","210").collect(Collectors.toSet()));
+        connections.put("99", Stream.of("122","235","74","235","74","235").collect(Collectors.toSet()));
+        connections.put("100", Stream.of("34","111").collect(Collectors.toSet()));
+        connections.put("101", Stream.of("110","226").collect(Collectors.toSet()));
+        connections.put("102", Stream.of("258","276").collect(Collectors.toSet()));
+        connections.put("103", Stream.of("51","109").collect(Collectors.toSet()));
+        connections.put("104", Stream.of("11","90","11","90","11","90").collect(Collectors.toSet()));
+        connections.put("105", Stream.of("177","195").collect(Collectors.toSet()));
+        connections.put("106", Stream.of("64","69").collect(Collectors.toSet()));
+        connections.put("107", Stream.of("28","284","133","196","191","272").collect(Collectors.toSet()));
+        connections.put("108", Stream.of("141","264").collect(Collectors.toSet()));
+        connections.put("109", Stream.of("91","103").collect(Collectors.toSet()));
+        connections.put("110", Stream.of("17","208","101","17","264").collect(Collectors.toSet()));
+        connections.put("111", Stream.of("22","100").collect(Collectors.toSet()));
+        connections.put("112", Stream.of("181","195").collect(Collectors.toSet()));
+        connections.put("113", Stream.of("245","297").collect(Collectors.toSet()));
+        connections.put("114", Stream.of("140").collect(Collectors.toSet()));
+        connections.put("115", Stream.of("178","184","290").collect(Collectors.toSet()));
+        connections.put("116", Stream.of("117","118","132").collect(Collectors.toSet()));
+        connections.put("117", Stream.of("116","118").collect(Collectors.toSet()));
+        connections.put("118", Stream.of("116","117").collect(Collectors.toSet()));
+        connections.put("119", Stream.of("34","58").collect(Collectors.toSet()));
+        connections.put("120", Stream.of("42","237").collect(Collectors.toSet()));
+        connections.put("121", Stream.of("260").collect(Collectors.toSet()));
+        connections.put("122", Stream.of("99","186","74","186").collect(Collectors.toSet()));
+        connections.put("123", Stream.of("95","145").collect(Collectors.toSet()));
+        connections.put("124", Stream.of("8","77").collect(Collectors.toSet()));
+        connections.put("125", Stream.of("134","270","134","270").collect(Collectors.toSet()));
+        connections.put("126", Stream.of("48","258","60","222").collect(Collectors.toSet()));
+        connections.put("127", Stream.of("186","225").collect(Collectors.toSet()));
+        connections.put("128", Stream.of("10","39").collect(Collectors.toSet()));
+        connections.put("129", Stream.of("85","267").collect(Collectors.toSet()));
+        connections.put("130", Stream.of("131","132").collect(Collectors.toSet()));
+        connections.put("131", Stream.of("130","189").collect(Collectors.toSet()));
+        connections.put("132", Stream.of("116","130").collect(Collectors.toSet()));
+        connections.put("133", Stream.of("107","146").collect(Collectors.toSet()));
+        connections.put("134", Stream.of("125","219","125","219").collect(Collectors.toSet()));
+        connections.put("135", Stream.of("64","171").collect(Collectors.toSet()));
+        connections.put("136", Stream.of("84","190","278").collect(Collectors.toSet()));
+        connections.put("137", Stream.of("205","297").collect(Collectors.toSet()));
+        connections.put("138", Stream.of("74").collect(Collectors.toSet()));
+        connections.put("139", Stream.of("40","263").collect(Collectors.toSet()));
+        connections.put("140", Stream.of("114","236").collect(Collectors.toSet()));
+        connections.put("141", Stream.of("108","212").collect(Collectors.toSet()));
+        connections.put("142", Stream.of("289","296").collect(Collectors.toSet()));
+        connections.put("143", Stream.of("159","205").collect(Collectors.toSet()));
+        connections.put("144", Stream.of("206","281").collect(Collectors.toSet()));
+        connections.put("145", Stream.of("90","92","90","92","90","92","7","89","39","222","89","123").collect(Collectors.toSet()));
+        connections.put("146", Stream.of("133","235").collect(Collectors.toSet()));
+        connections.put("147", Stream.of("150","282").collect(Collectors.toSet()));
+        connections.put("148", Stream.of("84","278").collect(Collectors.toSet()));
+        connections.put("149", Stream.of("162","207").collect(Collectors.toSet()));
+        connections.put("150", Stream.of("147","226").collect(Collectors.toSet()));
+        connections.put("151", Stream.of("49","258","60","196").collect(Collectors.toSet()));
+        connections.put("152", Stream.of("86").collect(Collectors.toSet()));
+        connections.put("153", Stream.of("154","246").collect(Collectors.toSet()));
+        connections.put("154", Stream.of("153","229","274").collect(Collectors.toSet()));
+        connections.put("155", Stream.of("224","283").collect(Collectors.toSet()));
+        connections.put("156", Stream.of("13","24","2","167","3","167","2","167").collect(Collectors.toSet()));
+        connections.put("157", Stream.of("23","232","13","29").collect(Collectors.toSet()));
+        connections.put("158", Stream.of("37","68").collect(Collectors.toSet()));
+        connections.put("159", Stream.of("143","277").collect(Collectors.toSet()));
+        connections.put("160", Stream.of("95","265").collect(Collectors.toSet()));
+        connections.put("161", Stream.of("25","44","25","44").collect(Collectors.toSet()));
+        connections.put("162", Stream.of("28","149").collect(Collectors.toSet()));
+        connections.put("163", Stream.of("11","82").collect(Collectors.toSet()));
+        connections.put("164", Stream.of("24","246","33","243","33","243").collect(Collectors.toSet()));
+        connections.put("165", Stream.of("93").collect(Collectors.toSet()));
+        connections.put("166", Stream.of("44","262","44","262").collect(Collectors.toSet()));
+        connections.put("167", Stream.of("14","156","14","156","14","156","13","188").collect(Collectors.toSet()));
+        connections.put("168", Stream.of("62","179","213").collect(Collectors.toSet()));
+        connections.put("169", Stream.of("239").collect(Collectors.toSet()));
+        connections.put("170", Stream.of("40","89").collect(Collectors.toSet()));
+        connections.put("171", Stream.of("61","135").collect(Collectors.toSet()));
+        connections.put("172", Stream.of("71","281").collect(Collectors.toSet()));
+        connections.put("173", Stream.of("16","98").collect(Collectors.toSet()));
+        connections.put("174", Stream.of("252").collect(Collectors.toSet()));
+        connections.put("175", Stream.of("252").collect(Collectors.toSet()));
+        connections.put("176", Stream.of("30","233").collect(Collectors.toSet()));
+        connections.put("177", Stream.of("105","238").collect(Collectors.toSet()));
+        connections.put("178", Stream.of("115","201").collect(Collectors.toSet()));
+        connections.put("179", Stream.of("168","180").collect(Collectors.toSet()));
+        connections.put("180", Stream.of("179","198").collect(Collectors.toSet()));
+        connections.put("181", Stream.of("76","112","285").collect(Collectors.toSet()));
+        connections.put("182", Stream.of("73","193").collect(Collectors.toSet()));
+        connections.put("183", Stream.of("42","43").collect(Collectors.toSet()));
+        connections.put("184", Stream.of("115","198").collect(Collectors.toSet()));
+        connections.put("185", Stream.of("236","280").collect(Collectors.toSet()));
+        connections.put("186", Stream.of("127","207","18","122","18","122").collect(Collectors.toSet()));
+        connections.put("187", Stream.of("57","231").collect(Collectors.toSet()));
+        connections.put("188", Stream.of("7","167").collect(Collectors.toSet()));
+        connections.put("189", Stream.of("30","131").collect(Collectors.toSet()));
+        connections.put("190", Stream.of("136","244").collect(Collectors.toSet()));
+        connections.put("191", Stream.of("196","211","28","258","107","276").collect(Collectors.toSet()));
+        connections.put("192", Stream.of("82","277","18","83","18","83","83","217").collect(Collectors.toSet()));
+        connections.put("193", Stream.of("5","182").collect(Collectors.toSet()));
+        connections.put("194", Stream.of("96","204").collect(Collectors.toSet()));
+        connections.put("195", Stream.of("105","112").collect(Collectors.toSet()));
+        connections.put("196", Stream.of("49","191","107","151").collect(Collectors.toSet()));
+        connections.put("197", Stream.of("271","272").collect(Collectors.toSet()));
+        connections.put("198", Stream.of("180","184").collect(Collectors.toSet()));
+        connections.put("199", Stream.of("269","288","269","288").collect(Collectors.toSet()));
+        connections.put("200", Stream.of("4","27","283","291").collect(Collectors.toSet()));
+        connections.put("201", Stream.of("178","281").collect(Collectors.toSet()));
+        connections.put("202", Stream.of("63","216").collect(Collectors.toSet()));
+        connections.put("203", Stream.of("32","246").collect(Collectors.toSet()));
+        connections.put("204", Stream.of("80","194").collect(Collectors.toSet()));
+        connections.put("205", Stream.of("137","143").collect(Collectors.toSet()));
+        connections.put("206", Stream.of("45","144").collect(Collectors.toSet()));
+        connections.put("207", Stream.of("149","186").collect(Collectors.toSet()));
+        connections.put("208", Stream.of("110","241").collect(Collectors.toSet()));
+        connections.put("209", Stream.of("75","290","75","234").collect(Collectors.toSet()));
+        connections.put("210", Stream.of("98","274").collect(Collectors.toSet()));
+        connections.put("211", Stream.of("11","191").collect(Collectors.toSet()));
+        connections.put("212", Stream.of("141").collect(Collectors.toSet()));
+        connections.put("213", Stream.of("53","168").collect(Collectors.toSet()));
+        connections.put("214", Stream.of("51","300").collect(Collectors.toSet()));
+        connections.put("215", Stream.of("41","275").collect(Collectors.toSet()));
+        connections.put("216", Stream.of("20","202").collect(Collectors.toSet()));
+        connections.put("217", Stream.of("192","282").collect(Collectors.toSet()));
+        connections.put("218", Stream.of("43","63").collect(Collectors.toSet()));
+        connections.put("219", Stream.of("134","221","134","221").collect(Collectors.toSet()));
+        connections.put("220", Stream.of("238","293").collect(Collectors.toSet()));
+        connections.put("221", Stream.of("75","219","75","219").collect(Collectors.toSet()));
+        connections.put("222", Stream.of("126","145").collect(Collectors.toSet()));
+        connections.put("223", Stream.of("95","259").collect(Collectors.toSet()));
+        connections.put("224", Stream.of("13","155","261","275","294").collect(Collectors.toSet()));
+        connections.put("225", Stream.of("127","295").collect(Collectors.toSet()));
+        connections.put("226", Stream.of("101","150").collect(Collectors.toSet()));
+        connections.put("227", Stream.of("294").collect(Collectors.toSet()));
+        connections.put("228", Stream.of("235","272","235","272").collect(Collectors.toSet()));
+        connections.put("229", Stream.of("154","240").collect(Collectors.toSet()));
+        connections.put("230", Stream.of("80","299").collect(Collectors.toSet()));
+        connections.put("231", Stream.of("9","187").collect(Collectors.toSet()));
+        connections.put("232", Stream.of("157","278").collect(Collectors.toSet()));
+        connections.put("233", Stream.of("1","176").collect(Collectors.toSet()));
+        connections.put("234", Stream.of("209","250").collect(Collectors.toSet()));
+        connections.put("235", Stream.of("99","228","99","228","99","146").collect(Collectors.toSet()));
+        connections.put("236", Stream.of("140","185").collect(Collectors.toSet()));
+        connections.put("237", Stream.of("61","120").collect(Collectors.toSet()));
+        connections.put("238", Stream.of("177","220").collect(Collectors.toSet()));
+        connections.put("239", Stream.of("59","169").collect(Collectors.toSet()));
+        connections.put("240", Stream.of("229","300").collect(Collectors.toSet()));
+        connections.put("241", Stream.of("208","264").collect(Collectors.toSet()));
+        connections.put("242", Stream.of("45").collect(Collectors.toSet()));
+        connections.put("243", Stream.of("164","294","164","294").collect(Collectors.toSet()));
+        connections.put("244", Stream.of("55","190","35","271").collect(Collectors.toSet()));
+        connections.put("245", Stream.of("113","280").collect(Collectors.toSet()));
+        connections.put("246", Stream.of("153","164","203","288").collect(Collectors.toSet()));
+        connections.put("247", Stream.of("272","284","272","284").collect(Collectors.toSet()));
+        connections.put("248", Stream.of("11","253").collect(Collectors.toSet()));
+        connections.put("249", Stream.of("13","48").collect(Collectors.toSet()));
+        connections.put("250", Stream.of("234","251").collect(Collectors.toSet()));
+        connections.put("251", Stream.of("5","250").collect(Collectors.toSet()));
+        connections.put("252", Stream.of("41","174","175").collect(Collectors.toSet()));
+        connections.put("253", Stream.of("94","248").collect(Collectors.toSet()));
+        connections.put("254", Stream.of("25","87","25","87").collect(Collectors.toSet()));
+        connections.put("255", Stream.of("68","88").collect(Collectors.toSet()));
+        connections.put("256", Stream.of("12","257").collect(Collectors.toSet()));
+        connections.put("257", Stream.of("59","256").collect(Collectors.toSet()));
+        connections.put("258", Stream.of("126","191","102","151").collect(Collectors.toSet()));
+        connections.put("259", Stream.of("26","223").collect(Collectors.toSet()));
+        connections.put("260", Stream.of("121","301").collect(Collectors.toSet()));
+        connections.put("261", Stream.of("224").collect(Collectors.toSet()));
+        connections.put("262", Stream.of("2","166","3","166").collect(Collectors.toSet()));
+        connections.put("263", Stream.of("8","139").collect(Collectors.toSet()));
+        connections.put("264", Stream.of("52","108","241","1","110").collect(Collectors.toSet()));
+        connections.put("265", Stream.of("160","302").collect(Collectors.toSet()));
+        connections.put("266", Stream.of("267").collect(Collectors.toSet()));
+        connections.put("267", Stream.of("129","266").collect(Collectors.toSet()));
+        connections.put("268", Stream.of("15","21").collect(Collectors.toSet()));
+        connections.put("269", Stream.of("78","199","78","199").collect(Collectors.toSet()));
+        connections.put("270", Stream.of("125","125").collect(Collectors.toSet()));
+        connections.put("271", Stream.of("197","244").collect(Collectors.toSet()));
+        connections.put("272", Stream.of("228","247","228","247","107","197").collect(Collectors.toSet()));
+        connections.put("273", Stream.of("26").collect(Collectors.toSet()));
+        connections.put("274", Stream.of("154","210").collect(Collectors.toSet()));
+        connections.put("275", Stream.of("215","224").collect(Collectors.toSet()));
+        connections.put("276", Stream.of("89","102","89","191").collect(Collectors.toSet()));
+        connections.put("277", Stream.of("159","192").collect(Collectors.toSet()));
+        connections.put("278", Stream.of("87","148","232","284","87","136","13").collect(Collectors.toSet()));
+        connections.put("279", Stream.of("62").collect(Collectors.toSet()));
+        connections.put("280", Stream.of("185","245").collect(Collectors.toSet()));
+        connections.put("281", Stream.of("144","172","94","201").collect(Collectors.toSet()));
+        connections.put("282", Stream.of("147","217").collect(Collectors.toSet()));
+        connections.put("283", Stream.of("155","200","291").collect(Collectors.toSet()));
+        connections.put("284", Stream.of("87","247","87","247","107","278").collect(Collectors.toSet()));
+        connections.put("285", Stream.of("72","181").collect(Collectors.toSet()));
+        connections.put("286", Stream.of("74","96").collect(Collectors.toSet()));
+        connections.put("287", Stream.of("93","301").collect(Collectors.toSet()));
+        connections.put("288", Stream.of("36","199","36","199","43","246").collect(Collectors.toSet()));
+        connections.put("289", Stream.of("94","142").collect(Collectors.toSet()));
+        connections.put("290", Stream.of("115","209").collect(Collectors.toSet()));
+        connections.put("291", Stream.of("42","200","283").collect(Collectors.toSet()));
+        connections.put("292", Stream.of("17","74").collect(Collectors.toSet()));
+        connections.put("293", Stream.of("220").collect(Collectors.toSet()));
+        connections.put("294", Stream.of("3","243","224","227","3","243").collect(Collectors.toSet()));
+        connections.put("295", Stream.of("76","225").collect(Collectors.toSet()));
+        connections.put("296", Stream.of("71","142").collect(Collectors.toSet()));
+        connections.put("297", Stream.of("113","137").collect(Collectors.toSet()));
+        connections.put("298", Stream.of("299").collect(Collectors.toSet()));
+        connections.put("299", Stream.of("230","298").collect(Collectors.toSet()));
+        connections.put("300", Stream.of("37","214","240").collect(Collectors.toSet()));
+        connections.put("301", Stream.of("260","287").collect(Collectors.toSet()));
+        connections.put("302", Stream.of("31","265").collect(Collectors.toSet()));
+
+        underground = new Graph<>(stations, connections);
+        routeFinder = new RouteFinder<>(underground, new HaversineScorer(), new HaversineScorer());
+    }
+
+    @Test
+    public void findRoute() {
+        List<Station> route = routeFinder.findRoute(underground.getNode("74"), underground.getNode("7"));
+
+        System.out.println(route.stream().map(Station::getName).collect(Collectors.toList()));
+    }
+}

algorithms-miscellaneous-2/src/test/java/com/baeldung/algorithms/astar/underground/Station.java

@@ -0,0 +1,42 @@
+package com.baeldung.algorithms.astar.underground;
+
+import java.util.StringJoiner;
+
+import com.baeldung.algorithms.astar.GraphNode;
+
+public class Station implements GraphNode {
+    private final String id;
+    private final String name;
+    private final double latitude;
+    private final double longitude;
+
+    public Station(String id, String name, double latitude, double longitude) {
+        this.id = id;
+        this.name = name;
+        this.latitude = latitude;
+        this.longitude = longitude;
+    }
+
+    @Override
+    public String getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public double getLatitude() {
+        return latitude;
+    }
+
+    public double getLongitude() {
+        return longitude;
+    }
+
+    @Override
+    public String toString() {
+        return new StringJoiner(", ", Station.class.getSimpleName() + "[", "]").add("id='" + id + "'")
+            .add("name='" + name + "'").add("latitude=" + latitude).add("longitude=" + longitude).toString();
+    }
+}

algorithms-miscellaneous-3/README.md

@@ -1,10 +1,21 @@
+## Algorithms - Miscellaneous
+
+This module contains articles about algorithms. Some classes of algorithms, e.g., [sorting](/algorithms-sorting) and
+[genetic algorithms](/algorithms-genetic), have their own dedicated modules. 
+
 ## Relevant Articles:
 
 - [Java Two Pointer Technique](https://www.baeldung.com/java-two-pointer-technique)
 - [Implementing Simple State Machines with Java Enums](https://www.baeldung.com/java-enum-simple-state-machine)
-- [Converting Between Roman and Arabic Numerals in Java](http://www.baeldung.com/java-convert-roman-arabic)
-- [Practical Java Examples of the Big O Notation](http://www.baeldung.com/java-algorithm-complexity)
+- [Converting Between Roman and Arabic Numerals in Java](https://www.baeldung.com/java-convert-roman-arabic)
+- [Practical Java Examples of the Big O Notation](https://www.baeldung.com/java-algorithm-complexity)
 - [Checking If a List Is Sorted in Java](https://www.baeldung.com/java-check-if-list-sorted)
 - [Checking if a Java Graph has a Cycle](https://www.baeldung.com/java-graph-has-a-cycle)
 - [A Guide to the Folding Technique in Java](https://www.baeldung.com/folding-hashing-technique)
 - [Creating a Triangle with for Loops in Java](https://www.baeldung.com/java-print-triangle)
+- [Efficient Word Frequency Calculator in Java](https://www.baeldung.com/java-word-frequency)
+- [Interpolation Search in Java](https://www.baeldung.com/java-interpolation-search)
+- [The K-Means Clustering Algorithm in Java](https://www.baeldung.com/java-k-means-clustering-algorithm)
+- [Creating a Custom Annotation in Java](https://www.baeldung.com/java-custom-annotation)
+- [Breadth-First Search Algorithm in Java](https://www.baeldung.com/java-breadth-first-search)
+- More articles: [[<-- prev]](/algorithms-miscellaneous-2) [[next -->]](/algorithms-miscellaneous-4)

algorithms-miscellaneous-3/pom.xml

@@ -54,6 +54,21 @@
             <version>1.1.0</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh-generator.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-bytecode</artifactId>
+            <version>${jmh-generator.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -73,5 +88,7 @@
         <commons-collections4.version>4.3</commons-collections4.version>
         <guava.version>28.0-jre</guava.version>
         <retrofit.version>2.6.0</retrofit.version>
+        <jmh-core.version>1.19</jmh-core.version>
+        <jmh-generator.version>1.19</jmh-generator.version>
     </properties>
 </project>

algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/breadthfirstsearch/BreadthFirstSearchAlgorithm.java

@@ -0,0 +1,54 @@
+package com.baeldung.algorithms.breadthfirstsearch;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.*;
+
+public class BreadthFirstSearchAlgorithm {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(BreadthFirstSearchAlgorithm.class);
+
+    public static <T> Optional<Tree<T>> search(T value, Tree<T> root) {
+        Queue<Tree<T>> queue = new ArrayDeque<>();
+        queue.add(root);
+
+        Tree<T> currentNode;
+        while (!queue.isEmpty()) {
+            currentNode = queue.remove();
+            LOGGER.info("Visited node with value: {}", currentNode.getValue());
+
+            if (currentNode.getValue().equals(value)) {
+                return Optional.of(currentNode);
+            } else {
+                queue.addAll(currentNode.getChildren());
+            }
+        }
+
+        return Optional.empty();
+    }
+
+    public static <T> Optional<Node<T>> search(T value, Node<T> start) {
+        Queue<Node<T>> queue = new ArrayDeque<>();
+        queue.add(start);
+
+        Node<T> currentNode;
+        Set<Node<T>> alreadyVisited = new HashSet<>();
+
+        while (!queue.isEmpty()) {
+            currentNode = queue.remove();
+            LOGGER.info("Visited node with value: {}", currentNode.getValue());
+
+            if (currentNode.getValue().equals(value)) {
+                return Optional.of(currentNode);
+            } else {
+                alreadyVisited.add(currentNode);
+                queue.addAll(currentNode.getNeighbors());
+                queue.removeAll(alreadyVisited);
+            }
+        }
+
+        return Optional.empty();
+    }
+
+}

algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/breadthfirstsearch/Node.java

@@ -0,0 +1,31 @@
+package com.baeldung.algorithms.breadthfirstsearch;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+public class Node<T> {
+
+    private T value;
+    private Set<Node<T>> neighbors;
+
+    public Node(T value) {
+        this.value = value;
+        this.neighbors = new HashSet<>();
+    }
+
+    public T getValue() {
+        return value;
+    }
+
+    public Set<Node<T>> getNeighbors() {
+        return Collections.unmodifiableSet(neighbors);
+    }
+
+    public void connect(Node<T> node) {
+        if (this == node) throw new IllegalArgumentException("Can't connect node to itself");
+        this.neighbors.add(node);
+        node.neighbors.add(this);
+    }
+
+}

algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/breadthfirstsearch/Tree.java

@@ -0,0 +1,34 @@
+package com.baeldung.algorithms.breadthfirstsearch;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class Tree<T> {
+
+    private T value;
+    private List<Tree<T>> children;
+
+    private Tree(T value) {
+        this.value = value;
+        this.children = new ArrayList<>();
+    }
+
+    public static <T> Tree<T> of(T value) {
+        return new Tree<>(value);
+    }
+
+    public T getValue() {
+        return value;
+    }
+
+    public List<Tree<T>> getChildren() {
+        return Collections.unmodifiableList(children);
+    }
+
+    public Tree<T> addChild(T value) {
+        Tree<T> newChild = new Tree<>(value);
+        children.add(newChild);
+        return newChild;
+    }
+}

algorithms-miscellaneous-3/src/main/java/com/baeldung/algorithms/bucketsort/IntegerBucketSorter.java

@@ -1,70 +0,0 @@
-package com.baeldung.bucketsort;
-
-import java.util.ArrayList;
-import java.util.Comparator;
-import java.util.List;
-
-public class IntegerBucketSorter implements Sorter<Integer> {
-
-    private final Comparator<Integer> comparator;
-
-    public IntegerBucketSorter(Comparator<Integer> comparator) {
-        this.comparator = comparator;
-    }
-
-    public IntegerBucketSorter() {
-        comparator = Comparator.naturalOrder();
-    }
-
-    public List<Integer> sort(List<Integer> arrayToSort) {
-
-        List<List<Integer>> buckets = splitIntoUnsortedBuckets(arrayToSort);
-
-        for(List<Integer> bucket  : buckets){
-            bucket.sort(comparator);
-        }
-
-        return concatenateSortedBuckets(buckets);
-    }
-
-    private List<Integer> concatenateSortedBuckets(List<List<Integer>> buckets){
-        List<Integer> sortedArray = new ArrayList<>();
-        int index = 0;
-        for(List<Integer> bucket : buckets){
-            for(int number : bucket){
-                sortedArray.add(index++, number);
-            }
-        }
-        return sortedArray;
-    }
-
-    private List<List<Integer>> splitIntoUnsortedBuckets(List<Integer> initialList){
-
-        final int[] codes = createHashes(initialList);
-
-        List<List<Integer>> buckets = new ArrayList<>(codes[1]);
-        for(int i = 0; i < codes[1]; i++) buckets.add(new ArrayList<>());
-
-        //distribute the data
-        for (int i : initialList) {
-            buckets.get(hash(i, codes)).add(i);
-        }
-        return buckets;
-
-    }
-
-    private int[] createHashes(List<Integer> input){
-        int m = input.get(0);
-        for (int i = 1; i < input.size(); i++) {
-            if (m < input.get(i)) {
-                m = input.get(i);
-            }
-        }
-        return new int[]{m, (int) Math.sqrt(input.size())};
-    }
-
-    private static int hash(int i, int[] code) {
-        return (int) ((double) i / code[0] * (code[1] - 1));
-    }
-
-}

algorithms-miscellaneous-3/src/test/java/com/baeldung/algorithms/breadthfirstsearch/BreadthFirstSearchAlgorithmUnitTest.java

@@ -0,0 +1,86 @@
+package com.baeldung.algorithms.breadthfirstsearch;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class BreadthFirstSearchAlgorithmUnitTest {
+
+    private Tree<Integer> root;
+    private Tree<Integer> rootFirstChild;
+    private Tree<Integer> depthMostChild;
+    private Tree<Integer> rootSecondChild;
+
+    private Node<Integer> start;
+    private Node<Integer> firstNeighbor;
+    private Node<Integer> firstNeighborNeighbor;
+    private Node<Integer> secondNeighbor;
+
+    @Test
+    void givenTree_whenSearchTen_thenRoot() {
+        initTree();
+        assertThat(BreadthFirstSearchAlgorithm.search(10, root)).isPresent().contains(root);
+    }
+
+    @Test
+    void givenTree_whenSearchThree_thenDepthMostValue() {
+        initTree();
+        assertThat(BreadthFirstSearchAlgorithm.search(3, root)).isPresent().contains(depthMostChild);
+    }
+
+    @Test
+    void givenTree_whenSearchFour_thenRootSecondChild() {
+        initTree();
+        assertThat(BreadthFirstSearchAlgorithm.search(4, root)).isPresent().contains(rootSecondChild);
+    }
+
+    @Test
+    void givenTree_whenSearchFive_thenNotFound() {
+        initTree();
+        assertThat(BreadthFirstSearchAlgorithm.search(5, root)).isEmpty();
+    }
+
+    private void initTree() {
+        root = Tree.of(10);
+        rootFirstChild = root.addChild(2);
+        depthMostChild = rootFirstChild.addChild(3);
+        rootSecondChild = root.addChild(4);
+    }
+
+    @Test
+    void givenNode_whenSearchTen_thenStart() {
+        initNode();
+        assertThat(BreadthFirstSearchAlgorithm.search(10, firstNeighborNeighbor)).isPresent().contains(start);
+    }
+
+    @Test
+    void givenNode_whenSearchThree_thenNeighborNeighbor() {
+        initNode();
+        assertThat(BreadthFirstSearchAlgorithm.search(3, firstNeighborNeighbor)).isPresent().contains(firstNeighborNeighbor);
+    }
+
+    @Test
+    void givenNode_whenSearchFour_thenSecondNeighbor() {
+        initNode();
+        assertThat(BreadthFirstSearchAlgorithm.search(4, firstNeighborNeighbor)).isPresent().contains(secondNeighbor);
+    }
+
+    @Test
+    void givenNode_whenSearchFive_thenNotFound() {
+        initNode();
+        assertThat(BreadthFirstSearchAlgorithm.search(5, firstNeighborNeighbor)).isEmpty();
+    }
+
+    private void initNode() {
+        start = new Node<>(10);
+        firstNeighbor = new Node<>(2);
+        start.connect(firstNeighbor);
+
+        firstNeighborNeighbor = new Node<>(3);
+        firstNeighbor.connect(firstNeighborNeighbor);
+        firstNeighborNeighbor.connect(start);
+
+        secondNeighbor = new Node<>(4);
+        start.connect(secondNeighbor);
+    }
+}

algorithms-miscellaneous-4/README.md

@@ -0,0 +1,14 @@
+## Algorithms - Miscellaneous
+
+This module contains articles about algorithms. Some classes of algorithms, e.g., [sorting](https://github.com/eugenp/tutorials/blob/algorithms-sorting) and [genetic algorithms](https://github.com/eugenp/tutorials/blob/algorithms-genetic), have their own dedicated modules.
+
+### Relevant articles:
+
+- [Multi-Swarm Optimization Algorithm in Java](https://www.baeldung.com/java-multi-swarm-algorithm)
+- [String Search Algorithms for Large Texts](https://www.baeldung.com/java-full-text-search-algorithms)
+- [Check If a String Contains All The Letters of The Alphabet](https://www.baeldung.com/java-string-contains-all-letters)
+- [Find the Middle Element of a Linked List](https://www.baeldung.com/java-linked-list-middle-element)
+- [Find Substrings That Are Palindromes in Java](https://www.baeldung.com/java-palindrome-substrings)
+- [Find the Longest Substring without Repeating Characters](https://www.baeldung.com/java-longest-substring-without-repeated-characters)
+- [Permutations of an Array in Java](https://www.baeldung.com/java-array-permutations)
+- More articles: [[<-- prev]](/algorithms-miscellaneous-3) [[next -->]](/algorithms-miscellaneous-5)

algorithms-miscellaneous-4/pom.xml

@@ -0,0 +1,51 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>algorithms-miscellaneous-4</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>algorithms-miscellaneous-4</name>
+    
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${org.assertj.core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.codehaus.mojo</groupId>
+                    <artifactId>exec-maven-plugin</artifactId>
+                    <version>${exec-maven-plugin.version}</version>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+
+    <properties>
+        <org.assertj.core.version>3.9.0</org.assertj.core.version>
+        <guava.version>27.0.1-jre</guava.version>
+    </properties>
+
+</project>

algorithms-miscellaneous-4/src/main/java/com/baeldung/algorithms/smallestinteger/SmallestMissingPositiveInteger.java

@@ -0,0 +1,37 @@
+package com.baeldung.algorithms.smallestinteger;
+
+import java.util.Arrays;
+
+public class SmallestMissingPositiveInteger {
+    public static int searchInSortedArray(int[] input) {
+        for (int i = 0; i < input.length; i++) {
+            if (i != input[i]) {
+                return i;
+            }
+        }
+
+        return input.length;
+    }
+
+    public static int searchInUnsortedArraySortingFirst(int[] input) {
+        Arrays.sort(input);
+        return searchInSortedArray(input);
+    }
+
+    public static int searchInUnsortedArrayBooleanArray(int[] input) {
+        boolean[] flags = new boolean[input.length];
+        for (int number : input) {
+            if (number < flags.length) {
+                flags[number] = true;
+            }
+        }
+
+        for (int i = 0; i < flags.length; i++) {
+            if (!flags[i]) {
+                return i;
+            }
+        }
+
+        return flags.length;
+    }
+}

algorithms-miscellaneous-4/src/test/java/com/baeldung/algorithms/smallestinteger/SmallestMissingPositiveIntegerUnitTest.java

@@ -0,0 +1,88 @@
+package com.baeldung.algorithms.smallestinteger;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class SmallestMissingPositiveIntegerUnitTest {
+    @Test
+    void givenArrayWithThreeMissing_whenSearchInSortedArray_thenThree() {
+        int[] input = new int[] {0, 1, 2, 4, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInSortedArray(input);
+
+        assertThat(result).isEqualTo(3);
+    }
+
+    @Test
+    void givenArrayWithOneAndThreeMissing_whenSearchInSortedArray_thenOne() {
+        int[] input = new int[] {0, 2, 4, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInSortedArray(input);
+
+        assertThat(result).isEqualTo(1);
+    }
+
+    @Test
+    void givenArrayWithoutMissingInteger_whenSearchInSortedArray_thenArrayLength() {
+        int[] input = new int[] {0, 1, 2, 3, 4, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInSortedArray(input);
+
+        assertThat(result).isEqualTo(input.length);
+    }
+
+    @Test
+    void givenArrayWithThreeMissing_whenSearchInUnsortedArraySortingFirst_thenThree() {
+        int[] input = new int[] {1, 4, 0, 5, 2};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArraySortingFirst(input);
+
+        assertThat(result).isEqualTo(3);
+    }
+
+    @Test
+    void givenArrayWithOneAndThreeMissing_whenSearchInUnsortedArraySortingFirst_thenOne() {
+        int[] input = new int[] {4, 2, 0, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArraySortingFirst(input);
+
+        assertThat(result).isEqualTo(1);
+    }
+
+    @Test
+    void givenArrayWithoutMissingInteger_whenSearchInUnsortedArraySortingFirst_thenArrayLength() {
+        int[] input = new int[] {4, 5, 1, 3, 0, 2};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArraySortingFirst(input);
+
+        assertThat(result).isEqualTo(input.length);
+    }
+
+    @Test
+    void givenArrayWithThreeMissing_whenSearchInUnsortedArrayBooleanArray_thenThree() {
+        int[] input = new int[] {1, 4, 0, 5, 2};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArrayBooleanArray(input);
+
+        assertThat(result).isEqualTo(3);
+    }
+
+    @Test
+    void givenArrayWithOneAndThreeMissing_whenSearchInUnsortedArrayBooleanArray_thenOne() {
+        int[] input = new int[] {4, 2, 0, 5};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArrayBooleanArray(input);
+
+        assertThat(result).isEqualTo(1);
+    }
+
+    @Test
+    void givenArrayWithoutMissingInteger_whenSearchInUnsortedArrayBooleanArray_thenArrayLength() {
+        int[] input = new int[] {4, 5, 1, 3, 0, 2};
+
+        int result = SmallestMissingPositiveInteger.searchInUnsortedArrayBooleanArray(input);
+
+        assertThat(result).isEqualTo(input.length);
+    }
+}

algorithms-miscellaneous-5/README.md

@@ -0,0 +1,12 @@
+## Algorithms - Miscellaneous
+
+This module contains articles about algorithms. Some classes of algorithms, e.g., [sorting](/../algorithms-sorting) and
+[genetic algorithms](/../algorithms-genetic), have their own dedicated modules. 
+
+### Relevant articles:
+
+- [Converting Between Byte Arrays and Hexadecimal Strings in Java](https://www.baeldung.com/java-byte-arrays-hex-strings)
+- [Reversing a Binary Tree in Java](https://www.baeldung.com/java-reversing-a-binary-tree)
+- [Find If Two Numbers Are Relatively Prime in Java](https://www.baeldung.com/java-two-relatively-prime-numbers)
+- [Knapsack Problem Implementation in Java](https://www.baeldung.com/java-knapsack)
+- More articles: [[<-- prev]](/../algorithms-miscellaneous-4)

algorithms-miscellaneous-5/pom.xml

@@ -0,0 +1,64 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>algorithms-miscellaneous-5</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>algorithms-miscellaneous-5</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>commons-codec</groupId>
+            <artifactId>commons-codec</artifactId>
+            <version>${commons-codec.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-math3</artifactId>
+            <version>${commons-math3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>pl.allegro.finance</groupId>
+            <artifactId>tradukisto</artifactId>
+            <version>${tradukisto.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${org.assertj.core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.codehaus.mojo</groupId>
+                    <artifactId>exec-maven-plugin</artifactId>
+                    <version>${exec-maven-plugin.version}</version>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+
+    <properties>
+        <tradukisto.version>1.0.1</tradukisto.version>
+        <org.assertj.core.version>3.9.0</org.assertj.core.version>
+        <commons-codec.version>1.11</commons-codec.version>
+        <commons-math3.version>3.6.1</commons-math3.version>
+    </properties>
+
+</project>

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/balancedbinarytree/BalancedBinaryTree.java

@@ -0,0 +1,33 @@
+package com.baeldung.algorithms.balancedbinarytree;
+
+public class BalancedBinaryTree {
+
+    public static boolean isBalanced(Tree tree) {
+        return isBalancedRecursive(tree, -1).isBalanced;
+    }
+
+    private static Result isBalancedRecursive(Tree tree, int depth) {
+        if (tree == null) {
+            return new Result(true, -1);
+        }
+
+        Result leftSubtreeResult = isBalancedRecursive(tree.left(), depth + 1);
+        Result rightSubtreeResult = isBalancedRecursive(tree.right(), depth + 1);
+
+        boolean isBalanced = Math.abs(leftSubtreeResult.height - rightSubtreeResult.height) <= 1;
+        boolean subtreesAreBalanced = leftSubtreeResult.isBalanced && rightSubtreeResult.isBalanced;
+        int height = Math.max(leftSubtreeResult.height, rightSubtreeResult.height) + 1;
+
+        return new Result(isBalanced && subtreesAreBalanced, height);
+    }
+
+    private static final class Result {
+        private final boolean isBalanced;
+        private final int height;
+
+        private Result(boolean isBalanced, int height) {
+            this.isBalanced = isBalanced;
+            this.height = height;
+        }
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/balancedbinarytree/Tree.java

@@ -0,0 +1,34 @@
+package com.baeldung.algorithms.balancedbinarytree;
+
+public class Tree {
+    private final int value;
+    private final Tree left;
+    private final Tree right;
+
+    public Tree(int value, Tree left, Tree right) {
+        this.value = value;
+        this.left = left;
+        this.right = right;
+    }
+
+    public int value() {
+        return value;
+    }
+
+    public Tree left() {
+        return left;
+    }
+
+    public Tree right() {
+        return right;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("[%s, %s, %s]",
+            value,
+            left == null ? "null" : left.toString(),
+            right == null ? "null" : right.toString()
+        );
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/binarygap/BinaryGap.java

@@ -0,0 +1,17 @@
+package com.baeldung.algorithms.binarygap;
+
+public class BinaryGap {
+    static int calculateBinaryGap(int n) {
+        return calculateBinaryGap(n >>> Integer.numberOfTrailingZeros(n), 0, 0);
+    }
+
+    static int calculateBinaryGap(int n, int current, int maximum) {
+        if (n == 0) {
+            return maximum;
+        } else if ((n & 1) == 0) {
+            return calculateBinaryGap(n >>> 1, current + 1, maximum);
+        } else {
+            return calculateBinaryGap(n >>> 1, 0, Math.max(maximum, current));
+        }
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/caesarcipher/CaesarCipher.java

@@ -0,0 +1,83 @@
+package com.baeldung.algorithms.caesarcipher;
+
+import org.apache.commons.math3.stat.inference.ChiSquareTest;
+
+import java.util.Arrays;
+import java.util.stream.IntStream;
+
+public class CaesarCipher {
+    private static final char LETTER_A = 'a';
+    private static final char LETTER_Z = 'z';
+    private static final int ALPHABET_SIZE = LETTER_Z - LETTER_A + 1;
+    private static final double[] ENGLISH_LETTERS_PROBABILITIES = {0.073, 0.009, 0.030, 0.044, 0.130, 0.028, 0.016, 0.035, 0.074, 0.002, 0.003, 0.035, 0.025, 0.078, 0.074, 0.027, 0.003, 0.077, 0.063, 0.093, 0.027, 0.013, 0.016, 0.005, 0.019, 0.001};
+
+    public String cipher(String message, int offset) {
+        StringBuilder result = new StringBuilder();
+
+        for (char character : message.toCharArray()) {
+            if (character != ' ') {
+                int originalAlphabetPosition = character - LETTER_A;
+                int newAlphabetPosition = (originalAlphabetPosition + offset) % ALPHABET_SIZE;
+                char newCharacter = (char) (LETTER_A + newAlphabetPosition);
+                result.append(newCharacter);
+            } else {
+                result.append(character);
+            }
+        }
+
+        return result.toString();
+    }
+
+    public String decipher(String message, int offset) {
+        return cipher(message, ALPHABET_SIZE - (offset % ALPHABET_SIZE));
+    }
+
+    public int breakCipher(String message) {
+        return probableOffset(chiSquares(message));
+    }
+
+    private double[] chiSquares(String message) {
+        double[] expectedLettersFrequencies = expectedLettersFrequencies(message.length());
+
+        double[] chiSquares = new double[ALPHABET_SIZE];
+
+        for (int offset = 0; offset < chiSquares.length; offset++) {
+            String decipheredMessage = decipher(message, offset);
+            long[] lettersFrequencies = observedLettersFrequencies(decipheredMessage);
+            double chiSquare = new ChiSquareTest().chiSquare(expectedLettersFrequencies, lettersFrequencies);
+            chiSquares[offset] = chiSquare;
+        }
+
+        return chiSquares;
+    }
+
+    private long[] observedLettersFrequencies(String message) {
+        return IntStream.rangeClosed(LETTER_A, LETTER_Z)
+          .mapToLong(letter -> countLetter((char) letter, message))
+          .toArray();
+    }
+
+    private long countLetter(char letter, String message) {
+        return message.chars()
+          .filter(character -> character == letter)
+          .count();
+    }
+
+    private double[] expectedLettersFrequencies(int messageLength) {
+        return Arrays.stream(ENGLISH_LETTERS_PROBABILITIES)
+          .map(probability -> probability * messageLength)
+          .toArray();
+    }
+
+    private int probableOffset(double[] chiSquares) {
+        int probableOffset = 0;
+        for (int offset = 0; offset < chiSquares.length; offset++) {
+            System.out.println(String.format("Chi-Square for offset %d: %.2f", offset, chiSquares[offset]));
+            if (chiSquares[offset] < chiSquares[probableOffset]) {
+                probableOffset = offset;
+            }
+        }
+
+        return probableOffset;
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/knapsack/Knapsack.java

@@ -0,0 +1,36 @@
+package com.baeldung.algorithms.knapsack;
+
+public class Knapsack {
+
+    public int knapsackRec(int[] w, int[] v, int n, int W) {
+        if (n <= 0) {
+            return 0;
+        } else if (w[n - 1] > W) {
+            return knapsackRec(w, v, n - 1, W);
+        } else {
+            return Math.max(knapsackRec(w, v, n - 1, W), v[n - 1] + knapsackRec(w, v, n - 1, W - w[n - 1]));
+        }
+    }
+
+    public int knapsackDP(int[] w, int[] v, int n, int W) {
+        if (n <= 0 || W <= 0) {
+            return 0;
+        }
+
+        int[][] m = new int[n + 1][W + 1];
+        for (int j = 0; j <= W; j++) {
+            m[0][j] = 0;
+        }
+
+        for (int i = 1; i <= n; i++) {
+            for (int j = 1; j <= W; j++) {
+                if (w[i - 1] > j) {
+                    m[i][j] = m[i - 1][j];
+                } else {
+                    m[i][j] = Math.max(m[i - 1][j], m[i - 1][j - w[i - 1]] + v[i - 1]);
+                }
+            }
+        }
+        return m[n][W];
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/balancedbinarytree/BalancedBinaryTreeUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.algorithms.balancedbinarytree;
+
+import org.junit.Test;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+
+public class BalancedBinaryTreeUnitTest extends BinaryTreeDataProvider {
+
+    @Test
+    public void givenBalancedTrees_whenCallingIsBalanced_ShouldReturnTrue() {
+        for (Tree tree : balancedTrees()) {
+            assertTrue(toString(tree) + " should be balanced", BalancedBinaryTree.isBalanced(tree));
+        }
+    }
+
+    @Test
+    public void givenUnbalancedTrees_whenCallingIsBalanced_ShouldReturnFalse() {
+        for (Tree tree : unbalancedTrees()) {
+            assertFalse(toString(tree) + " should not be balanced", BalancedBinaryTree.isBalanced(tree));
+        }
+    }
+
+    private String toString(Tree tree) {
+        return tree != null ? tree.toString() : "null";
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/balancedbinarytree/BinaryTreeDataProvider.java

@@ -0,0 +1,69 @@
+package com.baeldung.algorithms.balancedbinarytree;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+class BinaryTreeDataProvider {
+
+    static Collection<Tree> balancedTrees() {
+        return Arrays.asList(
+            null,
+            leaf(1),
+            tree(1, leaf(2), leaf(3)),
+            tree(
+                1,
+                leaf(2),
+                tree(3, leaf(4), null)
+            ),
+            tree(
+                1,
+                tree(
+                    2,
+                    tree(3, leaf(4), null),
+                    leaf(5)
+                ),
+                tree(
+                    6,
+                    leaf(7),
+                    tree(8, null, leaf(9))
+                )
+            )
+        );
+    }
+
+    static Collection<Tree> unbalancedTrees() {
+        return Arrays.asList(
+            tree(
+                1,
+                tree(2, leaf(3), null),
+                null
+            ),
+            tree(
+                1,
+                tree(
+                    2,
+                    tree(3, leaf(4), leaf(5)),
+                    null
+                ),
+                tree(6, leaf(7), null)
+            ),
+            tree(
+                1,
+                tree(2, leaf(3), null),
+                tree(
+                    4,
+                    tree(5, leaf(6), leaf(7)),
+                    null
+                )
+            )
+        );
+    }
+
+    private static Tree leaf(int value) {
+        return new Tree(value, null, null);
+    }
+
+    private static Tree tree(int value, Tree left, Tree right) {
+        return new Tree(value, left, right);
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/binarygap/BinaryGapUnitTest.java

@@ -0,0 +1,34 @@
+package com.baeldung.algorithms.binarygap;
+
+import static com.baeldung.algorithms.binarygap.BinaryGap.calculateBinaryGap;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class BinaryGapUnitTest {
+
+    @Test public void givenNoOccurrenceOfBoundedZeros_whenCalculateBinaryGap_thenOutputCorrectResult() {
+
+        int result = calculateBinaryGap(63);
+        assertEquals(0, result);
+    }
+
+    @Test public void givenTrailingZeros_whenCalculateBinaryGap_thenOutputCorrectResult() {
+
+        int result = calculateBinaryGap(40);
+        assertEquals(1, result);
+    }
+
+    @Test public void givenSingleOccurrenceOfBoundedZeros_whenCalculateBinaryGap_thenOutputCorrectResult() {
+
+        int result = calculateBinaryGap(9);
+        assertEquals(2, result);
+    }
+
+    @Test public void givenMultipleOccurrenceOfBoundedZeros_whenCalculateBinaryGap_thenOutputCorrectResult() {
+
+        int result = calculateBinaryGap(145);
+        assertEquals(3, result);
+    }
+
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/caesarcipher/CaesarCipherUnitTest.java

@@ -0,0 +1,83 @@
+package com.baeldung.algorithms.caesarcipher;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class CaesarCipherUnitTest {
+    private static final String SENTENCE = "he told me i could never teach a llama to drive";
+    private static final String SENTENCE_SHIFTED_THREE = "kh wrog ph l frxog qhyhu whdfk d oodpd wr gulyh";
+    private static final String SENTENCE_SHIFTED_TEN = "ro dyvn wo s myevn xofob dokmr k vvkwk dy nbsfo";
+
+    private CaesarCipher algorithm = new CaesarCipher();
+
+    @Test
+    void givenSentenceAndShiftThree_whenCipher_thenCipheredMessageWithoutOverflow() {
+        String cipheredSentence = algorithm.cipher(SENTENCE, 3);
+
+        assertThat(cipheredSentence)
+          .isEqualTo(SENTENCE_SHIFTED_THREE);
+    }
+
+    @Test
+    void givenSentenceAndShiftTen_whenCipher_thenCipheredMessageWithOverflow() {
+        String cipheredSentence = algorithm.cipher(SENTENCE, 10);
+
+        assertThat(cipheredSentence)
+          .isEqualTo(SENTENCE_SHIFTED_TEN);
+    }
+
+    @Test
+    void givenSentenceAndShiftThirtySix_whenCipher_thenCipheredLikeTenMessageWithOverflow() {
+        String cipheredSentence = algorithm.cipher(SENTENCE, 36);
+
+        assertThat(cipheredSentence)
+          .isEqualTo(SENTENCE_SHIFTED_TEN);
+    }
+
+    @Test
+    void givenSentenceShiftedThreeAndShiftThree_whenDecipher_thenOriginalSentenceWithoutOverflow() {
+        String decipheredSentence = algorithm.decipher(SENTENCE_SHIFTED_THREE, 3);
+
+        assertThat(decipheredSentence)
+          .isEqualTo(SENTENCE);
+    }
+
+    @Test
+    void givenSentenceShiftedTenAndShiftTen_whenDecipher_thenOriginalSentenceWithOverflow() {
+        String decipheredSentence = algorithm.decipher(SENTENCE_SHIFTED_TEN, 10);
+
+        assertThat(decipheredSentence)
+          .isEqualTo(SENTENCE);
+    }
+
+    @Test
+    void givenSentenceShiftedTenAndShiftThirtySix_whenDecipher_thenOriginalSentenceWithOverflow() {
+        String decipheredSentence = algorithm.decipher(SENTENCE_SHIFTED_TEN, 36);
+
+        assertThat(decipheredSentence)
+          .isEqualTo(SENTENCE);
+    }
+
+    @Test
+    void givenSentenceShiftedThree_whenBreakCipher_thenOriginalSentence() {
+        int offset = algorithm.breakCipher(SENTENCE_SHIFTED_THREE);
+
+        assertThat(offset)
+          .isEqualTo(3);
+
+        assertThat(algorithm.decipher(SENTENCE_SHIFTED_THREE, offset))
+          .isEqualTo(SENTENCE);
+    }
+
+    @Test
+    void givenSentenceShiftedTen_whenBreakCipher_thenOriginalSentence() {
+        int offset = algorithm.breakCipher(SENTENCE_SHIFTED_TEN);
+
+        assertThat(offset)
+          .isEqualTo(10);
+
+        assertThat(algorithm.decipher(SENTENCE_SHIFTED_TEN, offset))
+          .isEqualTo(SENTENCE);
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/knapsack/KnapsackUnitTest.java

@@ -0,0 +1,44 @@
+package com.baeldung.algorithms.knapsack;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class KnapsackUnitTest {
+
+    @Test
+    public void givenWeightsandValues_whenCalculateMax_thenOutputCorrectResult() {
+        final int[] w = new int[] { 23, 26, 20, 18, 32, 27, 29, 26, 30, 27 };
+        final int[] v = new int[] { 505, 352, 458, 220, 354, 414, 498, 545, 473, 543 };
+        final int n = 10;
+        final int W = 67;
+        final Knapsack knapsack = new Knapsack();
+
+        assertEquals(1270, knapsack.knapsackRec(w, v, n, W));
+        assertEquals(1270, knapsack.knapsackDP(w, v, n, W));
+    }
+
+    @Test
+    public void givenZeroItems_whenCalculateMax_thenOutputZero() {
+        final int[] w = new int[] {};
+        final int[] v = new int[] {};
+        final int n = 0;
+        final int W = 67;
+        final Knapsack knapsack = new Knapsack();
+
+        assertEquals(0, knapsack.knapsackRec(w, v, n, W));
+        assertEquals(0, knapsack.knapsackDP(w, v, n, W));
+    }
+
+    @Test
+    public void givenZeroWeightLimit_whenCalculateMax_thenOutputZero() {
+        final int[] w = new int[] { 23, 26, 20, 18, 32, 27, 29, 26, 30, 27 };
+        final int[] v = new int[] { 505, 352, 458, 220, 354, 414, 498, 545, 473, 543 };
+        final int n = 10;
+        final int W = 0;
+        final Knapsack knapsack = new Knapsack();
+
+        assertEquals(0, knapsack.knapsackRec(w, v, n, W));
+        assertEquals(0, knapsack.knapsackDP(w, v, n, W));
+    }
+}

algorithms-sorting/README.md

@@ -1,9 +1,20 @@
-## Relevant articles:
+## Algorithms - Sorting
 
-- [Bubble Sort in Java](http://www.baeldung.com/java-bubble-sort)
+This module contains articles about sorting algorithms.
+
+### Relevant articles:
+
+- [Bubble Sort in Java](https://www.baeldung.com/java-bubble-sort)
 - [Merge Sort in Java](https://www.baeldung.com/java-merge-sort)
 - [Quicksort Algorithm Implementation in Java](https://www.baeldung.com/java-quicksort)
 - [Insertion Sort in Java](https://www.baeldung.com/java-insertion-sort)
 - [Heap Sort in Java](https://www.baeldung.com/java-heap-sort)
 - [Shell Sort in Java](https://www.baeldung.com/java-shell-sort)
 - [Counting Sort in Java](https://www.baeldung.com/java-counting-sort)
+- [Sorting Strings by Contained Numbers in Java](https://www.baeldung.com/java-sort-strings-contained-numbers)
+- [How an In-Place Sorting Algorithm Works](https://www.baeldung.com/java-in-place-sorting)
+- [Selection Sort in Java](https://www.baeldung.com/java-selection-sort)
+- [Sorting Strings by Contained Numbers in Java](https://www.baeldung.com/java-sort-strings-contained-numbers)
+- [Radix Sort in Java](https://www.baeldung.com/java-radix-sort)
+- [Sorting a String Alphabetically in Java](https://www.baeldung.com/java-sort-string-alphabetically)
+- [Bucket Sort in Java](https://www.baeldung.com/java-bucket-sort)

algorithms-sorting/pom.xml

@@ -28,6 +28,12 @@
             <version>${lombok.version}</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>${junit-jupiter-api.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
@@ -52,6 +58,7 @@
         <commons-math3.version>3.6.1</commons-math3.version>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>
         <commons-codec.version>1.11</commons-codec.version>
+        <junit-jupiter-api.version>5.3.1</junit-jupiter-api.version>
     </properties>
 
 </project>

algorithms-sorting/src/main/java/com/baeldung/algorithms/bucketsort/IntegerBucketSorter.java

@@ -0,0 +1,68 @@
+package com.baeldung.bucketsort;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.LinkedList;
+import java.util.List;
+
+public class IntegerBucketSorter implements Sorter<Integer> {
+
+    private final Comparator<Integer> comparator;
+
+    public IntegerBucketSorter(Comparator<Integer> comparator) {
+        this.comparator = comparator;
+    }
+
+    public IntegerBucketSorter() {
+        comparator = Comparator.naturalOrder();
+    }
+
+    public List<Integer> sort(List<Integer> arrayToSort) {
+
+        List<List<Integer>> buckets = splitIntoUnsortedBuckets(arrayToSort);
+
+        for(List<Integer> bucket  : buckets){
+            bucket.sort(comparator);
+        }
+
+        return concatenateSortedBuckets(buckets);
+    }
+
+    private List<Integer> concatenateSortedBuckets(List<List<Integer>> buckets){
+        List<Integer> sortedArray = new LinkedList<>();
+        for(List<Integer> bucket : buckets){
+            sortedArray.addAll(bucket);
+        }
+        return sortedArray;
+    }
+
+    private List<List<Integer>> splitIntoUnsortedBuckets(List<Integer> initialList){
+
+        final int max = findMax(initialList);
+        final int numberOfBuckets = (int) Math.sqrt(initialList.size());
+
+        List<List<Integer>> buckets = new ArrayList<>();
+        for(int i = 0; i < numberOfBuckets; i++) buckets.add(new ArrayList<>());
+
+        //distribute the data
+        for (int i : initialList) {
+            buckets.get(hash(i, max, numberOfBuckets)).add(i);
+        }
+        return buckets;
+
+    }
+
+    private int findMax(List<Integer> input){
+        int m = Integer.MIN_VALUE;
+        for (int i : input){
+            m = Math.max(i, m);
+        }
+        return m;
+    }
+
+    private static int hash(int i, int max, int numberOfBuckets) {
+        return (int) ((double) i / max * (numberOfBuckets - 1));
+    }
+
+
+}

algorithms-sorting/src/main/java/com/baeldung/algorithms/stringsort/AnagramValidator.java

@@ -1,4 +1,4 @@
-package com.baeldung.string.sorting;
+package com.baeldung.algorithms.stringsort;
 
 import java.util.Arrays;
 

algorithms-sorting/src/test/java/com/baeldung/algorithms/stringsort/AnagramValidatorUnitTest.java

@@ -1,12 +1,10 @@
-package com.baeldung.string.sorting;
+package com.baeldung.algorithms.stringsort;
 
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-
 import org.junit.jupiter.api.Test;
 
-import com.baeldung.string.sorting.AnagramValidator;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 class AnagramValidatorUnitTest {
     

algorithms-sorting/src/test/java/com/baeldung/algorithms/stringsort/SortStringUnitTest.java

@@ -1,9 +1,9 @@
-package com.baeldung.string.sorting;
-
-import java.util.Arrays;
+package com.baeldung.algorithms.stringsort;
 
 import org.junit.jupiter.api.Test;
 
+import java.util.Arrays;
+
 import static org.assertj.core.api.Assertions.assertThat;
 
 class SortStringUnitTest {

animal-sniffer-mvn-plugin/README.md

@@ -1,3 +1,7 @@
-## Relevant articles:
+## Animal Sniffer Maven Plugin
 
-[Introduction to Animal Sniffer Maven Plugin](http://www.baeldung.com/maven-animal-sniffer)
+This module contains articles about the Animal Sniffer Maven Plugin
+
+### Relevant articles:
+
+[Introduction to Animal Sniffer Maven Plugin](https://www.baeldung.com/maven-animal-sniffer)

animal-sniffer-mvn-plugin/pom.xml

@@ -1,7 +1,6 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
     <artifactId>animal-sniffer-mvn-plugin</artifactId>
     <version>1.0-SNAPSHOT</version>
     <name>animal-sniffer-mvn-plugin</name>

annotations/README.md

@@ -0,0 +1,7 @@
+## Annotations
+
+This module contains articles about Java annotations
+
+### Relevant Articles:
+
+- [Java Annotation Processing and Creating a Builder](https://www.baeldung.com/java-annotation-processing-builder)

annotations/readme.md

@@ -1,2 +0,0 @@
-### Relevant Articles:
-- [Java Annotation Processing and Creating a Builder](http://www.baeldung.com/java-annotation-processing-builder)

antlr/README.md

@@ -1,3 +1,7 @@
+## ANTLR
+
+This module contains articles about ANTLR
+
 ### Relevant Articles: 
 
-- [Java with ANTLR](http://www.baeldung.com/java-antlr)
+- [Java with ANTLR](https://www.baeldung.com/java-antlr)

apache-avro/README.md

@@ -1,2 +1,6 @@
+## Apache Avro
+
+This module contains articles about Apache Avro
+
 ### Relevant Articles:
-- [Guide to Apache Avro](http://www.baeldung.com/java-apache-avro)
+- [Guide to Apache Avro](https://www.baeldung.com/java-apache-avro)

apache-avro/pom.xml

@@ -14,12 +14,6 @@
     </parent>
 
     <dependencies>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>${junit.version}</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-simple</artifactId>
@@ -46,15 +40,6 @@
 
     <build>
         <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <version>${compiler-plugin.version}</version>
-                <configuration>
-                    <source>${java.version}</source>
-                    <target>${java.version}</target>
-                </configuration>
-            </plugin>
             <plugin>
                 <groupId>org.apache.avro</groupId>
                 <artifactId>avro-maven-plugin</artifactId>
@@ -79,8 +64,6 @@
     </build>
 
     <properties>
-        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <compiler-plugin.version>3.5</compiler-plugin.version>
         <avro.version>1.8.2</avro.version>
         <slf4j.version>1.7.25</slf4j.version>
     </properties>

apache-bval/README.md

@@ -1,2 +1,7 @@
+## Apache BVal
+
+This module contains articles about Apache BVal
+
 ### Relevant Articles:
-- [Intro to Apache BVal](http://www.baeldung.com/apache-bval)
+
+- [Intro to Apache BVal](https://www.baeldung.com/apache-bval)

apache-curator/README.md

@@ -1,3 +1,7 @@
+## Apache Curator
+
+This module contains articles about Apache Curator
+
 ### Relevant Articles:
 
-- [Introduction to Apache Curator](http://www.baeldung.com/apache-curator)
+- [Introduction to Apache Curator](https://www.baeldung.com/apache-curator)

apache-cxf/README.md

@@ -1,6 +1,10 @@
+## Apache CXF
+
+This module contains articles about Apache CXF
+
 ## Relevant Articles:
-- [Introduction to Apache CXF Aegis Data Binding](http://www.baeldung.com/aegis-data-binding-in-apache-cxf)
-- [Apache CXF Support for RESTful Web Services](http://www.baeldung.com/apache-cxf-rest-api)
-- [A Guide to Apache CXF with Spring](http://www.baeldung.com/apache-cxf-with-spring)
-- [Introduction to Apache CXF](http://www.baeldung.com/introduction-to-apache-cxf)
+- [Introduction to Apache CXF Aegis Data Binding](https://www.baeldung.com/aegis-data-binding-in-apache-cxf)
+- [Apache CXF Support for RESTful Web Services](https://www.baeldung.com/apache-cxf-rest-api)
+- [A Guide to Apache CXF with Spring](https://www.baeldung.com/apache-cxf-with-spring)
+- [Introduction to Apache CXF](https://www.baeldung.com/introduction-to-apache-cxf)
 - [Server-Sent Events (SSE) In JAX-RS](https://www.baeldung.com/java-ee-jax-rs-sse)

apache-fop/README.md

@@ -1,5 +1,5 @@
-=========
+## Apache FOP
 
-## Core Java Cookbooks and Examples
+This module contains articles about Apache FOP
 
 ### Relevant Articles: 

apache-fop/pom.xml

@@ -1,7 +1,6 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-fop</artifactId>
     <version>0.1-SNAPSHOT</version>
     <name>apache-fop</name>

apache-geode/README.md

@@ -1,3 +1,7 @@
+## Apache Geode
+
+This module contains articles about Apache Geode
+
 ### Relevant Articles: 
 
 - [A Quick Guide to Apache Geode](https://www.baeldung.com/apache-geode)

apache-geode/pom.xml

@@ -19,25 +19,7 @@
             <artifactId>geode-core</artifactId>
             <version>${geode.core}</version>
         </dependency>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>${junit.version}</version>
-        </dependency>
     </dependencies>
-    
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.maven.plugins</groupId>
-                <artifactId>maven-compiler-plugin</artifactId>
-                <configuration>
-                    <source>${java.version}</source>
-                    <target>${java.version}</target>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
 	
     <properties>
         <geode.core>1.6.0</geode.core>

apache-meecrowave/README.md

@@ -1,3 +1,7 @@
+## Apache Meecrowave
+
+This module contains articles about Apache Meecrowave
+
 ### Relevant Articles: 
-================================
-- [Building a Microservice with Apache Meecrowave](http://www.baeldung.com/apache-meecrowave)
+
+- [Building a Microservice with Apache Meecrowave](https://www.baeldung.com/apache-meecrowave)

apache-meecrowave/pom.xml

@@ -1,7 +1,6 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-meecrowave</artifactId>
     <version>0.0.1</version>
     <name>apache-meecrowave</name>
@@ -38,13 +37,6 @@
             <version>${meecrowave-junit.version}</version>
             <scope>test</scope>
         </dependency>
-        <!-- https://mvnrepository.com/artifact/junit/junit -->
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <version>${junit.version}</version>
-            <scope>test</scope>
-        </dependency>
     </dependencies>
 	
     <build>