这个题的思路其实跟[LeetCode] 199. Binary Tree Right Side View_ Medium tag: BFS, Amazon里面我提到的left side view一样的思路, 只是返回的时候返回最后一个元素即可. 1. Constraints 1) root cannot be None, 所以edge case就是 1 2, Ideas BFS: T: O(n), S: O(n) n is the number of the...
https://leetcode.com/problems/find-bottom-left-tree-value/ 用BFS,层次遍历 /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public int findBottom...
LeetCode 513. Find Bottom Left Tree Value Given a binary tree, find the leftmost value in the last row of the tree. 就是拿到最后一层的第一个元素。 这个元素是最左下角的元素,不是最左侧的元素。 如果想实现 其实也很简单 就是维护更新每一层的第一个元素。 代码解读 class Solution { public ...
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ class Solution { public int sumOfLeftLeaves(TreeNode root) { int sum=0; //如果为null直接返回0 if(root==null){ retur...
【Leetcode_总结】513. 找树左下角的值 - python Q: 给定一个二叉树,在树的最后一行找到最左边的值。 示例 1: 示例 2: 链接:https://leetcode-cn.com/problems/find-bottom-left-tree-value/description/ 思路:层次遍历返回最底层最左节点 效率跟屎一样 代码:... ...
使用层序遍历思想 3、代码 1intfindBottomLeftValue(TreeNode*root) {2if(root ==NULL)3return0;4queue<TreeNode*>q;5q.push(root);67intval =0;8while(!q.empty()) {9intsize =q.size();10for(inti =0; i < size; i++) {11TreeNode *node =q.front();12if(node->left !=NULL)13q.pu...
* Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { private int impl(TreeNode root, boolean left) { ...