Valid Parentheses @Leetcode -- Python

http://oj.leetcode.com/problems/valid-parentheses/

 1 class Solution:
 2     # @return a boolean
 3     def isValid(self, s):
 4         if s == '':
 5             return True
 6         left = '([{'
 7         right = ')]}'
 8         stack = []
 9         for i in s:
10             if i == '(' or i == '[' or i == '{':
11                 stack.append(i)
12                 continue
13             for j in xrange(3):
14                 if i == right[j]:
15                     if not stack or stack[-1] != left[j]:
16                         return False
17                     else:
18                         stack.pop()
19                         continue
20         return not stack
21 # test
22 s = Solution()
23 print s.isValid('()')

 

posted @ 2014-05-08 16:16  sumnous  阅读(160)  评论(0)  编辑  收藏  举报