Checking Balanced Parenthesis

Author: altruistcoder

Diff for: balanced_parenthesis_check.cpp

@@ -0,0 +1,72 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+// function to check if parenthesis are balanced
+bool areParanthesisBalanced(string expr)
+{
+    stack<char> s;
+    char x;
+
+    // Traversing the Expression
+    for (int i=0; i<expr.length(); i++)
+    {
+        if (expr[i]=='('||expr[i]=='['||expr[i]=='{')
+        {
+            // Push the element in the stack
+            s.push(expr[i]);
+            continue;
+        }
+
+        // IF current current character is not opening
+        // bracket, then it must be closing. So stack
+        // cannot be empty at this point.
+        if (s.empty())
+           return false;
+
+        switch (expr[i])
+        {
+        case ')':
+
+            // Store the top element in a
+            x = s.top();
+            s.pop();
+            if (x=='{' || x=='[')
+                return false;
+            break;
+
+        case '}':
+
+            // Store the top element in b
+            x = s.top();
+            s.pop();
+            if (x=='(' || x=='[')
+                return false;
+            break;
+
+        case ']':
+
+            // Store the top element in c
+            x = s.top();
+            s.pop();
+            if (x =='(' || x == '{')
+                return false;
+            break;
+        }
+    }
+
+    // Check Empty Stack
+    return (s.empty());
+}
+int main()
+{
+    // string expr = "{()}[]";
+    string expr;
+    cout<<"Enter a String: ";
+    cin>>expr;
+    // cout<<s;
+    if(areParanthesisBalanced(expr))
+        cout << "Balanced";
+    else
+        cout << "Not Balanced";
+    return 0;
+}