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,…

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…

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], […

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 *…

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…

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…

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…

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…

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]…

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] ] class Solution { public: vector<vector<int> > levelOrder(TreeNode* root) { vector<vector<int> > res…