20 - Valid Parentheses

Details

Key	Value
Link	https://leetcode.com/problems/valid-parentheses/
Language	Python 3
Runtime	59 ms, faster than 16.02% of Python3 online submissions for Valid Parentheses
Memory Usage	13.9 MB, less than 24.44% of Python3 online submissions for Valid Parentheses
Datastructures	stack
Algorithms	iterator

Procedure

1. TBD...

Code

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