leetcode 刷题 132 133

class Solution: def minCut(self, s: str) -> int: f = [-1] + [len(s)-1 for _ in range(len(s))] for i in range(len(s)): for j in range(i+1,len(s)+1): if s[i:j] == s[i:j][::-1]: f[j] = min(f[j], f[i] + 1) return f[-1]

  

 

  
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class Solution: def minCut(self, s: str) -> int: n = len(s) dp = [i - 1 for i in range(0, n + 1)] # dp[i]: the minimum cuts needed for s[:i] for i in range(0, n + 1): j = 0 while i - j >= 0 and i + j < n and s[i + j] == s[i - j]: dp[i + j + 1] = min(dp[i + j + 1], dp[i - j] + 1) j += 1 j = 1 while i - j + 1 >= 0 and i + j < n and s[i - j + 1] == s[i + j]: dp[i + j + 1] = min(dp[i + j + 1], dp[i - j + 1] + 1) j += 1 return dp[n] 

  

 

  
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"""
# Definition for a Node.
class Node(object): def __init__(self, val, neighbors): self.val = val self.neighbors = neighbors
"""
class Solution(object): def cloneGraph(self, node): """ :type node: Node :rtype: Node """
		# 1. Search graph for all nodes node_copies = {} self.fill_copies(node, node_copies)
		# 2. Create copies of all nodes for val, n in node_copies.items(): n[1] = Node(val, None)
		# 3. Fill neighbors in copies for n in node_copies.values(): n[1].neighbors = [node_copies[n2.val][1] for n2 in n[0].neighbors]
		# (Return) return node_copies[node.val][1] def fill_copies(self, node, copies): copies[node.val] = [node, None] for n in node.neighbors: if n.val not in copies: self.fill_copies(n, copies)

  

 

  
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class Solution: def cloneGraph(self, node: 'Node') -> 'Node': return copy.deepcopy(node)

  

 

  
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class Solution: def cloneGraph(self, node: 'Node') -> 'Node': if not node: return node return self._clone(node, {}) def _clone(self, v, clone_map): if v in clone_map: return clone_map[v] clone = Node(v.val, []) clone_map[v] = clone for n in v.neighbors: clone.neighbors.append(self._clone(n, clone_map)) return clone

  

 

  
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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/90743317