leetcode#20 Valid Parentheses

1. 문제

• https://leetcode.com/problems/valid-parentheses/
  

2. 나의 풀이

2.1 stack을 이용해서 풀기

class Solution:
    def isValid(self, s: str) -> bool:
        stack = []
        result = []
        
        
        
        left_into_right_dict = {
            "(" : ")",
            "{": "}",
            "[": "]"
        }
        
        for char in s:
            # print(stack, char)
            if len(stack) > 0:
                top = stack[-1]
                # print(right_end.values())
                if char in left_into_right_dict.values():
                    # print("hahah", top)
                    if top in left_into_right_dict.keys() and char == left_into_right_dict[top]:
                        stack.pop()
                        continue
                stack.append(char)
                
                
            else:
                stack.append(char)
        
        if len(stack) < 1:
            return True
        return False

3. 남의 풀이

3.1 스택을 이용한 풀이

• 나의 풀이랑 크게 다르지 않음
• https://velog.io/@kgh732/Python-%EC%9C%BC%EB%A1%9C-%ED%91%B8%EB%8A%94-Leetcode20.-Valid-Parentheses
• https://velog.io/@yejinh/%EC%95%8C%EA%B3%A0%EB%A6%AC%EC%A6%98-LeetCode-Valid-Parentheses

Reference

1. 왜 스택을 쓰는 가?

• https://shahadmahmud.medium.com/checking-parentheses-balance-using-stack-ce939faca1c3

  Now, when the closing part comes, if it matches the corresponding opening part, it indicates that it is a balancing part and the parenthesis is removed from the stack.
  Thus if after processing the string if the stack is empty, the parentheses are balanced.