Missing Test Case - 20. Valid Parentheses

[chitizsambhav]

LeetCode Username

csambhav

Problem number, title, and link

20, Valid Parentheses,(https://leetcode.com/problems/valid-parentheses/)

Category of the bug

• Missing test Case (Incorrect/Inefficient Code getting accepted because of missing test cases)

Description of the bug

For the below Testcase
"()" at 8th index ']' is present. Ideally this should return False as there is no open bracket present in the stack, if stack is being used to implement. But even though my code is returning true, the correct output returned by Leetcode IDE is also true. And also all the test case are running.

Language used for code

Python3

Code used for Submit/Run operation

class Solution:
    def isValid(self, s: str) -> bool:
        stack = []
        for char in s:
            if char in ['(', '{', '[']:
                stack.append(char)
            elif char in [')', '}', ']']:
                if not stack:
                    return False
                elif char == ')':
                    if stack[-1]=='(':
                        stack.pop()
                    else:
                        return False
                elif char == '}':
                    if stack[-1]=='{':
                        stack.pop()
                    else:
                        return False
                elif char == ']':
                    if stack[-1]=='[':
                        stack.pop()
                    else:
                        return False
                
                    
        if stack:
            return False
        else:
            return True

Expected behavior

For the testcase: "()" it should return false as per given description

Screenshots

Additional context