要求: 树的层级遍历 思路: 1.两个队列,q1 q2 ,root放到q1 2.q1首元素出列,判断是否有左右孩子,有的话,放入q2.(循环此步骤值得q1为空) 3.q1 = q2,重复2,直到q1为空.…

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   7return its leve…

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 DFS BFS 日期 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,nul…

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.…

思路: 与Binary Tree Level Order Traversal I 几乎一样.只是最后将结果存放在栈里,然后在栈里再传给向量即可. 再次总结思路: 两个queue,先把第一个放进q1,循环q1是否为空,不为空就读取并出列,如果root有孩子就放入q2,最后清空q2. 注意: for循环的时候不要使用vector.size()这类作为最大值判断,由于vector的size可能不断的减小,这回导致遍历不完的情况发生. 即: int count = sret.size(); ;i< co…

1. Unique Binary Search Trees Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example,Given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 思路:和 Unique Binar…

原题地址:http://oj.leetcode.com/problems/binary-tree-level-order-traversal-ii/ 题意: 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…

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 tr…

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…

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 本题收获: 1.vector<vector<int>>的用法 vector<vector<int> >注意<int>后面的空格,vector<vector<int>>表示的是二位向量. 输出格式(后面代码),不知道大小时,在vector中用push_back(vector<int>()) 2.树用迭代 题目: Given a binary tr…

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 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 II My Submissions QuestionEditorial Solution Total Accepted: 79742 Total Submissions: 234887 Difficulty: Easy Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to ri…

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 tr…

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…

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…

Binary Tree Level Order Traversal OJ: https://oj.leetcode.com/problems/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…

LeetCode: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 ord…

题目: 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 orde…

Binary Tree Level Order Traversal 二叉树的层序遍历 两种方式: 1.用两个queue交替表示每一层的节点 2.用两个node,一个表示当前层的最后一个节点,一个表示下一层的最后一个节点 /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x…

Question 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…

Binary Tree Level Order Traversal Total Accepted: 79463 Total Submissions: 259292 Difficulty: Easy 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,…

Binary Tree Level Order Traversal 题目链接 题目要求: 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…

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 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…

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,…

描述 给出一棵二叉树,返回其节点值的层次遍历(逐层从左往右访问) 样例 给一棵二叉树 {3,9,20,#,#,15,7} : 3 / \ 9 20 / \ 15 7 返回他的分层遍历结果: [ [3], [9,20], [15,7] ] 挑战 挑战1:只使用一个队列去实现它 挑战2:用BFS算法来做 代码 GitHub 的源代码,请访问下面的链接: https://github.com/cwiki-us/java-tutorial/blob/master/src/test/java/com/os…

原文题目: 102. Binary Tree Level Order Traversal 107. Binary Tree Level Order Traversal II 读题: 102. 层序遍历二叉树,每一层作为一个数组,从上到下输出 107.层序遍历二叉树,每一层作为一个数组,反过来从下到上输出 两者只有最后一行的存储方式不一致 class Solution(object): def levelOrder(self, root): """ :type root: Tr…

Binary Tree Level Order Traversal II 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…