二叉树的层次遍历 /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: vector<vector<int>> levelOrder(TreeNo…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7] ] 层序…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree [3,9,20,null,null,15,7] / \ / \ return its level order traversal as: [ [], [,], [,] ] 二叉树的层次遍历使用队列来实现,…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7] ] /*…

基础为用队列实现二叉树的层序遍历,本题变体是分别存储某一层的元素,那么只要知道,每一层的元素都是上一层的子元素,那么只要在while循环里面加个for循环,将当前队列的值(即本层元素)全部访问后再执行下一个循环就可以了. C++代码: /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val…

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 BFS DFS 日期 题目地址:https://leetcode.com/problems/binary-tree-level-order-traversal/ 题目描述 Given a binary tree, return the level order traversal of its nodes' values. (ie, from left…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example: Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7…

题目: Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7]…

题目: Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], […

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7…

题目描述: Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example: Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7] ] 解…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7…

这道题是LeetCode里的第102道题. 题目要求: 给定一个二叉树,返回其按层次遍历的节点值. (即逐层地,从左到右访问所有节点). 例如: 给定二叉树: [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 返回其层次遍历结果: [ [3], [9,20], [15,7] ] 解题代码: /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *…

网址:https://leetcode.com/problems/binary-tree-level-order-traversal/ 参考:https://www.cnblogs.com/grandyang/p/4051321.html 二叉树的层次遍历的做法是维护一个队列,不断使节点入队,使用了val后即出队.结束标志是队列是否为空 主要难度在于要分别提取出每层的val 我们可把在树的一层节点全部入列后队列的长度作为for循环的判断依据 /** * Definition for a bina…

给定一个二叉树,返回其按层次遍历的节点值. (即zhu'ceng'de,从左到右访问).例如:给定二叉树: [3,9,20,null,null,15,7],    3   / \  9  20    /  \   15   7返回其层次遍历结果为:[  [3],  [9,20],  [15,7]]详见:https://leetcode.com/problems/binary-tree-level-order-traversal/description/ Java实现: /** * Definit…

按层遍历树,要用到queue class Solution { public: vector<vector<int>> levelOrder(TreeNode* root) { vector<vector<int>> ret; //ahd(root) //a(ret) queue<TreeNode*> que; //a(que) if(!root) return ret; que.push(root); //dsp while(!que.empt…

Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root). For example:Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its bottom-up level or…

翻译 给定一个二叉树,返回从下往上遍历经过的每一个节点的值. 从左往右,从叶子到节点. 比如: 给定的二叉树是 {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 返回它从下往上的遍历结果: [ [15,7], [9,20], [3] ] 原文 Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, lev…

Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root). For example: Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its bottom-up level order t…

题目: LeetCode Premium Subscription Problems Pick One Mock Articles Discuss Book fengsehng 102. Binary Tree Level Order Traversal My Submissions QuestionEditorial Solution Total Accepted: 98313 Total Submissions: 302608 Difficulty: Easy Given a binary…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7] ] 层序…

Binary Tree Level Order Traversal 题目描述: Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order…

Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root). For example:Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 return its bottom-up level or…

Binary Tree Level Order Traversal Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traver…

Given a binary tree, return the vertical order traversal of its nodes' values. (ie, from top to bottom, column by column). If two nodes are in the same row and column, the order should be from left to right. Examples 1: Input: [3,9,20,null,null,15,7]…

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its level order traversal as: [ [3], [9,20], [15,7] ] 分层…

要求 对二叉树进行层序遍历 实现 返回结果为双重向量,对应树的每层元素 队列的每个元素是一个pair对,存树节点和其所在的层信息 1 Definition for a binary tree node. 2 struct TreeNode { 3 int val; 4 TreeNode *left; 5 TreeNode *right; 6 TreeNode(int x) : val(x), left(NULL), right(NULL) {} 7 }; 8 9 class Solution {…