1.题目描述 2.分析 使用递归. 3.代码 vector<string> ans; vector<string> binaryTreePaths(TreeNode* root) { if (root == NULL) return ans; leafPath(root,""); return ans; } void leafPath(TreeNode *root, string s) { if (root == NULL) return ; if (root-…

Binary Tree Paths Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: ["1->2->5", "1->3"] Credits:Special thanks to @jianchao.li.fighter f…

一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: ["1->2->5&q…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 递归 迭代 日期 题目地址:https://leetcode.com/problems/binary-tree-paths/#/description 题目描述 Given a binary tree, return all root-to-leaf paths. Note: A leaf is a node with no children. Ex…

Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: ["1->2->5", "1->3"] Credits:Special thanks to @jianchao.li.fighter for adding this pro…

Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: ["1->2->5", "1->3"] 简单的遍历查找路径问题,代码如下: /** * Definition for a binary tree node. * struc…

Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: ["1->2->5", "1->3"] 代码如下: /** * Definition for a binary tree node. * struct TreeNode {…

题目: Given a binary tree, return the inorder traversal of its nodes' values. For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,3,2]. Note: Recursive solution is trivial, could you do it iteratively? 说明:1)下面有两种实现:递归(Recursive )与非递归(迭代iterati…

Given a binary tree, flatten it to a linked list in-place. For example,Given 1 / \ 2 5 / \ \ 3 4 6 The flattened tree should look like: 1 \ 2 \ 3 \ 4 \ 5 \ 6 Hints: If you notice carefully in the flattened tree, each node's right child points to the…

题目: Given preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. 说明: 1)二叉树可空 2)思路:a.根据前序遍历的特点, 知前序序列(PreSequence)的首个元素(PreSequence[0])为二叉树的根(root),  然后在中序序列(InSequence)中查找此根(…

这是悦乐书的第199次更新,第206篇原创 01 看题和准备 今天介绍的是LeetCode算法题中Easy级别的第62题(顺位题号是257).给定二叉树,返回所有根到叶路径.例如: 输入: 1 / \ 2 3 \ 5 输出:["1-> 2-> 5","1-> 3"] 说明:所有根到叶路径是:1-> 2-> 5, 1-> 3 注意:叶子是没有子节点的节点. 本次解题使用的开发工具是eclipse,jdk使用的版本是1.8,环境是wi…

1.题目描述 2.问题分析 使用层序遍历 3.代码 vector<int> v; vector<int> rightSideView(TreeNode* root) { if (root == NULL) return v; queue<TreeNode*> q; q.push(root); while (!q.empty()) { int size = q.size(); ; i < size; i++) { TreeNode *node = q.front()…

1.题目描述 2.问题分析 使用递归 3.代码 TreeNode* pruneTree(TreeNode* root) { if (root == NULL) return NULL; prun(root); return root; } void prun(TreeNode *root) { if (root == NULL) return; if (!has_ones(root->left)) root->left = NULL; if (!has_ones(root->right)…

1.题目描述 2.分析 找出最大元素,然后分割数组调用. 3.代码 TreeNode* constructMaximumBinaryTree(vector<int>& nums) { int size = nums.size(); ) return NULL; TreeNode *dummy = ); maxcont(dummy->left, , size-, nums); return dummy->left; } void maxcont(TreeNode* &…

1.题目描述 2.题目分析 先遍历,再反转. 3.代码 vector<vector<int>> levelOrderBottom(TreeNode* root) { vector<vector<int>> ans; if (root == NULL) return ans; queue<TreeNode*> q; q.push(root); vector<int> v; while (!q.empty()) { int size =…

1.题目描述 2.分析 利用递归实现. 3.代码 int findTilt(TreeNode* root) { if (root == NULL) ; ; nodesTilt(root,ans); return ans; } int nodesTilt(TreeNode *root, int & ans) { if (root == NULL) ; int tiltleft = nodesTilt(root->left, ans); int tiltright = nodesTilt(roo…

1.题目描述 2.问题分析 递归 3.代码 vector<int> postorderTraversal(TreeNode* root) { vector<int> v; postBorder(root,v); return v; } void postBorder(TreeNode *root, vector<int> &v) { if (root == NULL) return ; postBorder(root->left, v); postBord…

1.题目描述 2.问题分析 利用递归. 3.代码 vector<int> preorderTraversal(TreeNode* root) { vector<int> v; preBorder(root, v); return v; } void preBorder(TreeNode *root, vector<int> &v) { if (root == NULL) return ; v.push_back(root->val); preBorder(…

剑指offer 面试题39:判断平衡二叉树 提交网址:  http://www.nowcoder.com/practice/8b3b95850edb4115918ecebdf1b4d222?tpId=13&tqId=11192 时间限制:1秒       空间限制:32768K      参与人数:2481 题目描述 输入一棵二叉树,判断该二叉树是否是平衡二叉树. 分析: 平衡二叉树定义 递归解法 AC代码: #include<iostream> #include<vector&…

257. Binary Tree Paths Total Accepted: 29282 Total Submissions: 113527 Difficulty: Easy Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: ["1->2->5",…

Given a binary tree, return all root-to-leaf paths.Example Given the following binary tree: 1 /   \2     3 \  5 All root-to-leaf paths are: [  "1->2->5",  "1->3"] LeetCode上的原题,请参见我之前的博客Binary Tree Paths. 解法一: class Solution {…

257. Binary Tree Paths Easy Given a binary tree, return all root-to-leaf paths. Note: A leaf is a node with no children. Example: Input: 1 / \ 2 3 \ 5 Output: ["1->2->5", "1->3"] Explanation: All root-to-leaf paths are: 1->…

Binary Tree Paths Given a binary tree, return all root-to-leaf paths. Given the following binary tree: 1 / \ 2 3 \ 5 All root-to-leaf paths are: [ "1->2->5", "1->3" ] As mentioned in the problem we want to get all root-to-leaf…

Problem Link: http://oj.leetcode.com/problems/binary-tree-postorder-traversal/ The post-order-traversal of a binary tree is a classic problem, the recursive way to solve it is really straightforward, the pseudo-code is as follows. RECURSIVE-POST-ORDE…

一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 来源: https://leetcode.com/problems/binary-tree-level-order-traversal-ii/ Given a binary tree, return the bottom-up level order traversal of its nodes' values.…

一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 来源: https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/ Given a binary tree, return the zigzag level order traversal of its nodes' values…

Given preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. For example, given preorder = [3,9,20,15,7] inorder = [9,3,15,20,7] Return the following binary tree: 3 / \ 9 20…

Given inorder and postorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. For example, given inorder = [9,3,15,20,7] postorder = [9,15,7,20,3] Return the following binary tree: 3 / \ 9 2…

Given inorder and postorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. For example, given inorder = [9,3,15,20,7] postorder = [9,15,7,20,3] Return the following binary tree: 3 / \ 9 2…

LeetCode--Diameter of Binary Tree Question Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass…