#Definition for a binary tree node.#class TreeNode(object):#def __init__(self, x):#self.val = x#self.left = None#self.right = None"""利用堆栈先进后出的特点"""classSolution(object):defpreorderTraversal(self, root):""":type root: TreeNode :rtype: List[int]"""result=[] slack=...
https://leetcode.com/problems/binary-tree-postorder-traversal/ Given a binary tree, return thepostordertraversal of its nodes' values. For example: Given binary tree{1,#,2,3}, 1 \ 2 / 3 return[3,2,1]. Note:Recursive solution is trivial, could you do it iteratively? 后续遍历二叉树,...
Left != nil || root.Right != nil { return root } // 此时当前子树中的所有子结点都是 0 ,需要修剪掉 return nil } 题目链接: Binary Tree Pruning: leetcode.com/problems/b 二叉树剪枝: leetcode.cn/problems/bi LeetCode 日更第 235 天,感谢阅读至此的你 欢迎点赞、收藏鼓励支持小满...
Python 代码 栈 + 循环实现 # Definition for a binary tree node. # class TreeNode: # def __init__(self, val=0, left=None, right=None): # self.val = val # self.left = left # self.right = right class Solution: def binaryTreePaths(self, root: TreeNode) -> List[str]: res = ...
LeetCode Top 100 Liked Questions 236. Lowest Common Ancestor of a Binary Tree (Java版; Medium) 题目描述 Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined betw...
Can you solve this real interview question? Lowest Common Ancestor of a Binary Tree - Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia [https://en.wikipedia.org/wi
Given the root of a binary tree, return the inorder traversal of its nodes' values. Example 1: Input: root = [1,null,2,3] Output: [1,3,2] Explanation: Example 2: Input: root = [1,2,3,4,5,null,8,null,null,6,7,9] Output: [4,2,6,5,7,1,3,9,8] Explanation: Example...
图片来源:https://leetcode.com/articles/binary-tree-right-side-view/ 对于时间复杂度来说,基本上都是O(n),因为要访问所有的点。 对于空间复杂度来说,BFS取决于扫描过程中每层的node数,就是树的宽度,而DFS取决于扫描过程中树的深度。最坏情况两个都是O(n)。
二维树状数组Binary Indexed Tree LeetCode题目:308. Range Sum Query 2D - Mutable Given a 2D matrixmatrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1,col1) and lower right corner (row2,col2). ...
leetcode-863-All Nodes Distance K in Binary Tree,Converttreetoindirectgraph,thenuseBFStogetKdistancefromtarget.Error:DonotfullyunderstandtheBFS,whenwantstogetsmallestdistance