leetcode 刷题 124 125

# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None

class Solution: def maxPathSum(self, root: TreeNode) -> int: # def maxPath(root):
# if not root: return 0, float("-inf")
# lPath, lMax = maxPath(root.left)
# rPath, rMax = maxPath(root.right)
# return max(lPath,rPath,0) + root.val, max(root.val + max(0,lPath) + max(0,rPath),lMax,rMax) # return maxPath(root)[1] res = [-float("inf")] def dfs(node): if not node: return -float("inf") l, r = dfs(node.left), dfs(node.right) mx = max(node.val, l + node.val, r + node.val) res[0] = max(res[0], mx, node.val + l + r) return mx dfs(root) return res[0]

  

 

  
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class Solution: def isPalindrome(self, s: str) -> bool: """ :type s: str :rtype: bool """ s = re.sub('[^a-zA-Z0-9]', '', s) return s.lower() == s[::-1].lower()

  

 

  
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class Solution: def isPalindrome(self, s): """ :type s: str :rtype: bool """ s = ''.join(filter(str.isalnum,s)).lower() return s==s[::-1]

  

 

  
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最快的

import re
class Solution(object): def isPalindrome(self, s): """ :type s: str :rtype: bool """ s = re.sub(r'[^\w]','',s) s = s.lower() print (s) return s == s[::-1]

  

 

  
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文章来源: maoli.blog.csdn.net，作者：刘润森！，版权归原作者所有，如需转载，请联系作者。

原文链接：maoli.blog.csdn.net/article/details/90738434