}private:voidlevelOrder(TreeNode* root,intcurrLevel) {if(root == NULL)return;if(res.empty() || currLevel > (res.size() -1)) res.push_back(vector<int>()); res[currLevel].push_back(root->val); levelOrder(root->left, currLevel +1); levelOrder(root->right, currLevel +1); } ...
1/**2* Definition for a binary tree node.3* struct TreeNode {4* int val;5* TreeNode *left;6* TreeNode *right;7* TreeNode(int x) : val(x), left(NULL), right(NULL) {}8* };9*/10classSolution {11public:12vector<vector<int>> levelOrder(TreeNode*root) {13vector<vector<int>>...
Given a binary tree, return thebottom-up level ordertraversal 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 1. 2. 3. 4. 5. return its bottom-up level orde...
=root){val queue=LinkedList<TreeNode>()queue.offer(root)while(queue.isNotEmpty()){val levelList=mutableListOf<Int>()val size=queue.size// 此处的for循环会把当前 level 层的所有元素poll出来,同时把下一层待遍历的节点放入队列for(iin0..size-1){// removes the head (first element)...
这道题目跟上道题目很相似 Leetcode: Binary Tree Level Order Traversal ,唯一不同的就是返回结果是从子叶节点到根节点,所以我们只需要将结果翻转下就好了! 参考代码: /** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; ...
102. 二叉树的层序遍历 - 给你二叉树的根节点 root ,返回其节点值的 层序遍历 。 (即逐层地,从左到右访问所有节点)。 示例 1: [https://assets.leetcode.com/uploads/2021/02/19/tree1.jpg] 输入:root = [3,9,20,null,null,15,7] 输出:[[3],[9,20],[15,7]]
这道题和LeetCode笔记:107. Binary Tree Level Order Traversal II是姊妹题,解题思路都是一样的,只是结果要求的顺序是反的,同样有两种方法,也就是经常说到的DFS深度优先遍历和BFS广度优先遍历。 BFS: 广度优先遍历就是一层层地攻略过去,把每一层的所有节点都记录下来再走向下一层。因为每层会有多个节点,不是简...
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: ...
seal-azarashi/leetcode#26 hroc135/leetcode#26 olsen-blue/Arai60#27 103. Binary Tree Zigzag Level Order Traversal 58b6ace olsen-blue reviewed Mar 2, 2025 View reviewed changes 103/step3.cpp vector<TreeNode*> current_level_nodes = {root}; while (!current_level_nodes.empty()) { ...
Binary Tree Zigzag Level Order Traversal Given a binary tree, return thezigzag level ordertraversal of its nodes' values. (ie, from left to right, then right to left for the next level and alterna ...