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题目描述： 方法一：迭代 class Solution: def flatten(self, root: TreeNode) -> None: """ Do not return anything, modify root in-place instead. """ cur = root while 阅读全文
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恢复内容开始 题目描述： 方法一：O(n) O(n) class Solution: def sortedListToBST(self, head: ListNode) -> TreeNode: nums = [] while head: nums.append(head.val) head = h 阅读全文
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题目描述： 方法一：O(n) O(n) class Solution: def buildTree(self, inorder: List[int], postorder: List[int]) -> TreeNode: assert len(inorder)==len(postorder) if 阅读全文
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题目描述： 方法一： # Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None class 阅读全文
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题目描述： 方法一： # Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None class 阅读全文
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题目描述： 方法一：递归O(n) O(n) # Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = 阅读全文
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题目描述： 方法一：递归 # Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None cla 阅读全文
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题目描述： 方法一：动态规划 O(n^2) O(n) class Solution: def numTrees(self, n: int) -> int: dp = [0]*(n+1) dp[0],dp[1] = 1,1 for i in range(2,n+1): for j in range(1 阅读全文