Grokking Data Structures & Algorithms for Coding Interviews

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Solution: Balanced Parentheses

Problem Statement

Given a string s containing (, ), [, ], {, and } characters. Determine if a given string of parentheses is balanced.

A string of parentheses is considered balanced if every opening parenthesis has a corresponding closing parenthesis in the correct order.

Example 1:

Input: String s = "{[()]}";
Expected Output: true
Explanation: The parentheses in this string are perfectly balanced. Every opening parenthesis '{', '[', '(' has a corresponding closing parenthesis '}', ']', ')' in the correct order.

Example 2:

.....

.....

.....

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Mohammed Dh Abbas

Mohammed Dh Abbas

· 2 years ago

class Solution:
    def isValid(self, s):
        stack = []
        for char in s: 
            if char == '{' or char == '[' or char == '(':
                stack.append(char)
            else:
                popped = stack.pop()
                if popped == '{' and char != '}':
                    return False
                elif popped == '[' and char != ']':
                    return False
                elif popped == '(' and char != ')':
                    return False
                   
        return len(stack) == 0
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