Merge pull request prabhupant#67 from braceritchie/master

prabhupant · web-flow · commit f8b9345886f4 · 2019-10-09T22:22:03.000+05:30
Determine if an expression is balanced using stack
diff --git a/data_structures/stack/balanced_expression.py b/data_structures/stack/balanced_expression.py
@@ -0,0 +1,24 @@
+# simple program to check if an expression is balanced using stack
+stack = []
+def checkBalanced(expr):
+    for i in expr:
+        if i == "{" or i == "[" or i == "(":
+            stack.append(i)
+        elif i == "}" or i == "]" or i == ")":
+            temp = stack.pop()
+            if i == "}" and temp != "{":
+                return False
+            elif i == "]" and temp != "[":
+                return False
+            elif i == ")" and temp != "(":
+                return False
+
+    return True
+
+# main function
+expr = input()
+result = checkBalanced(expr)
+if result:
+    print("Expression is balanced")
+else:
+    print("Expression is not balanced")
