LeetCode - 020
LeetCode - 020
咸鱼学Python
发布于 2019-06-18 19:46:33
发布于 2019-06-18 19:46:33
代码可运行
运行总次数：0
代码可运行
原题
https://leetcode.com/problems/valid-parentheses/
题干
Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.
An input string is valid if:
Open brackets must be closed by the same type of brackets. Open brackets must be closed in the correct order. Note that an empty string is also considered valid.
Example 1:
Input: "()" Output: true Example 2:
Input: "()[]{}" Output: true Example 3:
Input: "(]" Output: false Example 4:
Input: "([)]" Output: false Example 5:
Input: "{[]}" Output: true
这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的这是凑字数的
解
class Solution:
def isValid(self, s):
"""
:type s: str
:rtype: bool
"""
while '[]' in s or '()' in s or '{}' in s:
s = s.replace('[]','').replace('()','').replace('{}','')
return len(s) == 0解
class Solution:
def isValid(self, s):
"""
:type s: str
:rtype: bool
"""
stack = []
left = '({['
right = ']})'
for chart in s:
if chart in left:
stack.append(chart)
if chart in right:
if not stack:
return False
temp = stack.pop()
if chart == '}' and temp != '{':
return False
if chart == ']' and temp != '[':
return False
if chart == ')' and temp != '(':
return False
return stack == []本文参与 腾讯云自媒体同步曝光计划，分享自微信公众号。
原始发表：2019-06-14，如有侵权请联系 cloudcommunity@tencent.com 删除
评论
登录后参与评论
推荐阅读
目录
腾讯云开发者
