Given a binary tree, find the leftmost value in the last row of the tree. Example 1: Input: 2 / \ 1 3 Output: 1 Example 2: Input: 1 / \ 2 3 / / \ 4 5 6 / 7 Output: 7 Note: You may assume the tree (i.e., the given root node) is not NULL. 这个题的思路其实跟[Lee…

lc 513 Find Bottom Left Tree Value 513 Find Bottom Left Tree Value Given a binary tree, find the leftmost value in the last row of the tree. Example 1: Input: 2 / \ 1 3 Output: 1 Example 2: Input: 1 / \ 2 3 / / \ 4 5 6 / 7 Output: 7 Note: You may ass…

Given n nodes labeled from 0 to n-1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges make up a valid tree. Example 1: Input: n = 5, and edges = [[0,1], [0,2], [0,3], [1,4]] Output: true Exam…

Question 513. Find Bottom Left Tree Value Solution 题目大意: 给一个二叉树,求最底层,最左侧节点的值 思路: 按层遍历二叉树,每一层第一个被访问的节点就是该层最左侧的节点 Java实现: public int findBottomLeftValue(TreeNode root) { Queue<TreeNode> nodeQueue = new LinkedList<>(); nodeQueue.offer(root); // 向…

Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level and alternate between). For example:Given binary tree [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 retur…

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 Date 题目地址:https://leetcode.com/problems/find-bottom-left-tree-value/#/description 题目描述 Given a binary tree, find the leftmost value in the last row of the tree. Example…

原题 Given a binary tree, find the leftmost value in the last row of the tree. Example 1: Input: 2 / 1 3 Output: 1 Example 2: Input: 1 / \ 2 3 / / \ 4 5 6 / 7 Output: 7 Note: You may assume the tree (i.e., the given root node) is not NULL. 解析 查找最后一层最左侧…

Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom. Example: Input: [1,2,3,null,5,null,4] Output: [1, 3, 4] Explanation: 1 <--- / \ 2 3 <--- \ \ 5 4 <--- 这…

给定一个二叉树,在树的最后一行找到最左边的值. 详见:https://leetcode.com/problems/find-bottom-left-tree-value/description/ C++: 方法一: /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(…

Given a binary tree, find the leftmost value in the last row of the tree. Example 1: Input: 2 / \ 1 3 Output: 1 Example 2: Input: 1 / \ 2 3 / / \ 4 5 6 / 7 Output: 7 Note: You may assume the tree (i.e., the given root node) is not NULL. Solution 1: D…