【[LeetCode]题解（python）：100 Same Tree】的更多相关文章

<LeetCode OJ> 100. Same Tree

100. Same Tree Total Accepted: 100129 Total Submissions: 236623 Difficulty: Easy Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identical and the nodes have t…

LeetCode Javascript实现 100. Same Tree 171. Excel Sheet Column Number

100. Same Tree /** * Definition for a binary tree node. * function TreeNode(val) { * this.val = val; * this.left = this.right = null; * } */ /** * @param {TreeNode} p * @param {TreeNode} q * @return {boolean} */ var isSameTree = function(p, q) { if(p…

[LeetCode 题解]: Validate Binary Search Tree

Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node contains only nodes with keys…

leetcode题解：Construct Binary Tree from Inorder and Postorder Traversal（根据中序和后序遍历构造二叉树）

题目: Given inorder and postorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. 说明: 1)实现与根据先序和中序遍历构造二叉树相似,题目参考请进 算法思想 中序序列:C.B.E.D.F.A.H.G.J.I   后序序列:C.E.F.D.B.H.J.I.G.A   递归思路: 根据后序遍历的特点,…

LeetCode题解之Balanced Binary Tree

1.题目描述 2.问题分析 DFS. 3.代码 bool isBalanced(TreeNode* root) { if (root == NULL) return true; && isBalanced(root->left) && isBalanced(root->right); } int height(TreeNode *node) { if (node == NULL) ; if (node->left == NULL && no…

LeetCode题解：Flatten Binary Tree to Linked List：别人的递归！

总是在看完别人的代码之后,才发现自己的差距! 我的递归: 先把左侧扁平化,再把右侧扁平化. 然后找到左侧最后一个节点,把右侧移动过去. 然后把左侧整体移到右侧,左侧置为空. 很复杂吧! 如果节点很长的话,这个耗时是很大的.O(n^2) ?差不多了! 菜逼啊!时间估计都错了!!! 时间是多少呢? while 最左侧的数,会不断被遍历!是这样的.大概会被遍历o(n)次 所以还是O(n^2)? 反正是复杂了. void flatten(struct TreeNode* root) { if(root…

LeetCode题解之Univalued Binary Tree

1.题目描述 2.问题分析 遍历一遍树,然后将所有节点的数值放入到一个set中,最后检查set中元素的个数是否为1. 3.代码 bool isUnivalTree(TreeNode* root) { set<int> s; preOrder(root, s); ; } void preOrder(TreeNode* root, set<int> &s) { if (root == NULL) return; s.insert(root->val); preOrder(…

【LeetCode题解】二叉树的遍历

我准备开始一个新系列[LeetCode题解],用来记录刷LeetCode题,顺便复习一下数据结构与算法. 1. 二叉树 二叉树(binary tree)是一种极为普遍的数据结构,树的每一个节点最多只有两个节点--左孩子结点与右孩子结点.C实现的二叉树: struct TreeNode { int val; struct TreeNode *left; // left child struct TreeNode *right; // right child }; DFS DFS的思想非常朴素:根据…

[LeetCode 题解]: Binary Tree Preorder Traversal

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述 Given a binary tree, return the preorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. Note: Recursive sol…

[LeetCode 题解]: Symmetric Tree

前言   [LeetCode 题解]系列传送门:  http://www.cnblogs.com/double-win/category/573499.html   1.题目描述   Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree is symmetric: 1 / \ 2 2 / \ / \ 3…