Multidimentional ArrayList (#5795)

* Multidimentional ArrayList

* Adding code for 3-D ArrayList

* Removing comment

* Fixing indentation

* Spellcheck

core-java-collections/src/main/java/com/baeldung/list/multidimensional/ArrayListOfArrayList.java

@@ -0,0 +1,37 @@
+package com.baeldung.list.multidimensional;
+
+import java.util.ArrayList;
+
+public class ArrayListOfArrayList {
+
+    public static void main(String args[]) {
+
+        int vertex = 5;
+        ArrayList<ArrayList<Integer>> graph = new ArrayList<>(vertex);
+
+        //Initializing each element of ArrayList with ArrayList
+        for(int i=0; i< vertex; i++) {
+            graph.add(new ArrayList<Integer>());
+        }
+
+        //We can add any number of columns to each row
+        graph.get(0).add(1);
+        graph.get(0).add(5);
+        graph.get(1).add(0);
+        graph.get(1).add(2);
+        graph.get(2).add(1);
+        graph.get(2).add(3);
+        graph.get(3).add(2);
+        graph.get(3).add(4);
+        graph.get(4).add(3);
+        graph.get(4).add(5);
+
+        //Printing all the edges
+        for(int i=0; i<vertex; i++) {
+            for(int j=0; j<graph.get(i).size(); j++) {
+                System.out.println("Edge between vertex "+i+"and "+graph.get(i).get(j));
+            }
+        }
+    }
+
+}

core-java-collections/src/main/java/com/baeldung/list/multidimensional/ThreeDimensionalArrayList.java

@@ -0,0 +1,45 @@
+package com.baeldung.list.multidimensional;
+
+import java.util.ArrayList;
+
+public class ThreeDimensionalArrayList {
+
+    public static void main(String args[]) {
+        
+        int x_axis_length = 2;
+        int y_axis_length = 2;
+        int z_axis_length = 2;
+        ArrayList< ArrayList< ArrayList<String> > > space = new ArrayList<>(x_axis_length);
+
+        //Initializing each element of ArrayList with ArrayList< ArrayList<String> >
+        for(int i=0; i< x_axis_length; i++) {
+            space.add(new ArrayList< ArrayList<String> >(y_axis_length));
+            for(int j =0; j< y_axis_length; j++) {
+                space.get(i).add(new ArrayList<String>(z_axis_length));
+            }
+        }
+
+        //Set Red color for points (0,0,0) and (0,0,1)
+        space.get(0).get(0).add("Red");
+        space.get(0).get(0).add("Red");
+        //Set Blue color for points (0,1,0) and (0,1,1)
+        space.get(0).get(1).add("Blue");
+        space.get(0).get(1).add("Blue");
+        //Set Green color for points (1,0,0) and (1,0,1)
+        space.get(1).get(0).add("Green");
+        space.get(1).get(0).add("Green");
+        //Set Yellow color for points (1,1,0) and (1,1,1)
+        space.get(1).get(1).add("Yellow");
+        space.get(1).get(1).add("Yellow");
+
+        //Printing colors for all the points
+        for(int i=0; i<x_axis_length; i++) {
+            for(int j=0; j<y_axis_length; j++) {
+                for(int k=0; k<z_axis_length; k++) {
+                    System.out.println("Color of point ("+i+","+j+","+k+") is :"+space.get(i).get(j).get(k));
+                }
+            }
+        }
+    }
+
+}