ParenCheckergit status

src/main/java/io/zipcoder/ParenChecker.java

@@ -1,4 +1,86 @@
 package io.zipcoder;
 
+
 public class ParenChecker {
+
+    static class stack {
+        int top = -1;
+        char items[] = new char[100];
+
+        void push(char x) {
+            if (top == 99) {
+                System.out.println("Stack full");
+            } else {
+                items[++top] = x;
+            }
+        }
+
+        char pop() {
+            if (top == -1) {
+                System.out.println("Underflow error");
+                return '\0';
+            } else {
+                char element = items[top];
+                top--;
+                return element;
+            }
+        }
+
+        boolean isEmpty() {
+            return (top == -1) ? true : false;
+        }
+    }
+
+    /* Returns true if character1 and character2
+       are matching left and right Parenthesis */
+    static boolean isMatchingPair(char character1, char character2) {
+        if (character1 == '(' && character2 == ')')
+            return true;
+        else if (character1 == '{' && character2 == '}')
+            return true;
+        else if (character1 == '[' && character2 == ']')
+            return true;
+        else
+            return false;
+    }
+
+
+    static boolean areParenthesisBalanced(String exp) {
+        /* Declare an empty character stack */
+        stack stack = new stack();
+
+
+        for (int i = 0; i < exp.length(); i++) {
+            char s = exp.charAt(i);
+
+            if (s == '{' || s == '(' || s == '[')
+                stack.push (s);
+            if (s == '}' || s == ')' || s == ']') {
+
+                if (stack.isEmpty()) {
+                    return false;
+                } else if (!isMatchingPair(stack.pop(), s)) {
+                    return false;
+                }
+            }
+        }
+        if (stack.isEmpty()) {
+            return true; /*balanced*/
+        } else {   /*not balanced*/
+            return false;
+        }
+    }
+
+    /* UTILITY FUNCTIONS */
+    /*driver program to test above functions*/
+    public static void main(String[] args) {
+        String exp = " '{', '(', ')', '}', '[', ']' ";
+        if (areParenthesisBalanced(exp))
+            System.out.println("Balanced ");
+        else
+            System.out.println("Not Balanced ");
+    }
 }
+
+
+

src/test/java/io/zipcoder/ParenCheckerTest.java

@@ -5,4 +5,46 @@ import org.junit.Test;
 
 public class ParenCheckerTest {
 
+    @Test
+    public void isMatchingPair() {
+
+        boolean expected = false;
+        boolean actual = ParenChecker.isMatchingPair('{',')');
+       Assert.assertEquals(expected, actual);
+
+    }
+
+    @Test
+    public void isMatchingPair2() {
+
+        boolean expected = true;
+        boolean actual = ParenChecker.isMatchingPair('[',']');
+        Assert.assertEquals(expected, actual);
+
+    }
+
+
+    @Test
+    public void areParenthesisBalanced() {
+        ParenChecker balanced = new ParenChecker();
+        String str = "()[]{}[][]";
+
+        boolean expected = true;
+        boolean acutal = ParenChecker.areParenthesisBalanced(str);
+
+        Assert.assertEquals(true,acutal);
+
+    }
+
+    @Test
+    public void areParenthesisBalanced2() {
+        ParenChecker balanced = new ParenChecker();
+        String str = "([}])))";
+
+        boolean expected = false;
+        boolean acutal = ParenChecker.areParenthesisBalanced(str);
+
+        Assert.assertEquals(false,acutal);
+
+    }
 }