Merge pull request #8300 from iamshwetabhardwaj/master

BAEL-3481

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/balancedbrackets/BalancedBracketsUsingDeque.java

@@ -0,0 +1,36 @@
+package com.baeldung.algorithms.balancedbrackets;
+
+import java.util.Deque;
+import java.util.LinkedList;
+
+public class BalancedBracketsUsingDeque {
+
+    public boolean isBalanced(String str) {
+        if (null == str || ((str.length() % 2) != 0)) {
+            return false;
+        } else {
+            char[] ch = str.toCharArray();
+            for (char c : ch) {
+                if (!(c == '{' || c == '[' || c == '(' || c == '}' || c == ']' || c == ')')) {
+                    return false;
+                }
+
+            }
+        }
+
+        Deque<Character> deque = new LinkedList<>();
+        for (char ch : str.toCharArray()) {
+            if (ch == '{' || ch == '[' || ch == '(') {
+                deque.addFirst(ch);
+            } else {
+                if (!deque.isEmpty() && ((deque.peekFirst() == '{' && ch == '}') || (deque.peekFirst() == '[' && ch == ']') || (deque.peekFirst() == '(' && ch == ')'))) {
+                    deque.removeFirst();
+                } else {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/balancedbrackets/BalancedBracketsUsingString.java

@@ -0,0 +1,27 @@
+package com.baeldung.algorithms.balancedbrackets;
+
+public class BalancedBracketsUsingString {
+
+    public boolean isBalanced(String str) {
+        if (null == str || ((str.length() % 2) != 0)) {
+            return false;
+        } else {
+            char[] ch = str.toCharArray();
+            for (char c : ch) {
+                if (!(c == '{' || c == '[' || c == '(' || c == '}' || c == ']' || c == ')')) {
+                    return false;
+                }
+
+            }
+        }
+
+        while (str.contains("()") || str.contains("[]") || str.contains("{}")) {
+            str = str.replaceAll("\\(\\)", "")
+                .replaceAll("\\[\\]", "")
+                .replaceAll("\\{\\}", "");
+        }
+        return (str.length() == 0);
+
+    }
+
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/balancedbrackets/BalancedBracketsUsingDequeUnitTest.java

@@ -0,0 +1,76 @@
+package com.baeldung.algorithms.balancedbrackets;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BalancedBracketsUsingDequeUnitTest {
+    private BalancedBracketsUsingDeque balancedBracketsUsingDeque;
+
+    @Before
+    public void setup() {
+        balancedBracketsUsingDeque = new BalancedBracketsUsingDeque();
+    }
+
+    @Test
+    public void givenNullInput_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced(null);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEmptyString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenInvalidCharacterString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("abc[](){}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenOddLengthString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{[]()}}}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{[]()}}}}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthUnbalancedString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{[(])}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{[()]}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{[[(())]]}}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenAnotherBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{([])}}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenUnBalancedString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingDeque.isBalanced("{{)[](}}");
+        assertThat(result).isFalse();
+    }
+
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/balancedbrackets/BalancedBracketsUsingStringUnitTest.java

@@ -0,0 +1,76 @@
+package com.baeldung.algorithms.balancedbrackets;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BalancedBracketsUsingStringUnitTest {
+    private BalancedBracketsUsingString balancedBracketsUsingString;
+
+    @Before
+    public void setup() {
+        balancedBracketsUsingString = new BalancedBracketsUsingString();
+    }
+
+    @Test
+    public void givenNullInput_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced(null);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEmptyString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingString.isBalanced("");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenInvalidCharacterString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("abc[](){}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenOddLengthString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{[]()}}}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{[]()}}}}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthUnbalancedString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("{[(])}");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    public void givenEvenLengthBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingString.isBalanced("{[()]}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{[[(())]]}}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenAnotherBalancedString_whenCheckingForBalance_shouldReturnTrue() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{([])}}");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    public void givenUnBalancedString_whenCheckingForBalance_shouldReturnFalse() {
+        boolean result = balancedBracketsUsingString.isBalanced("{{)[](}}");
+        assertThat(result).isFalse();
+    }
+
+}