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,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its bottom-up level order traversal as: [ [15,7...
代码: 1vector<vector<int> > levelOrder(TreeNode *root) {2vector<vector<int> >orders;3if(root ==NULL)4returnorders;56vector<int>vtmp;7queue<TreeNode*>tque;8tque.push(root);9tque.push(NULL);1011intsize =2;12intcount =0;13intzero =0;//该层的NULL数14while(!tque.empty()){15...
方法一: 使用 LeetCode: 102. Binary Tree Level Order Traversal 的方法。在偶数次写入时,翻转写入的序列。 方法二: 使用两个栈存每行的数据,奇数行先存左孩子,再存右孩子,偶数行先存右孩子,再存左孩子。 AC 代码 方法一 /** * Definition for a binary tree node. * struct TreeNode...
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...
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: ...
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 ...
LeetCode Binary Tree Level Order Traversal II LeetCode解题之Binary Tree Level Order Traversal II 原题 实现树的广度优先遍历的倒序遍历。即从最底层依次向上遍历,每一层上的数据依照从左到右的顺序排列。 注意点: 无 样例: 输入: 输出: 解题思路 直接复用了 Binary Tree Level Order Traversal 的代码。
4.Balanced Binary Tree - 判断平衡二叉树 DFS 5.Path Sum - 二叉树路径求和判断DFS 题目概述: Given a binary tree, return thelevel ordertraversal of its nodes' values. (ie, from left to right, level by level). For example: Given binary tree{3,9,20,#,#,15,7}, ...
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 alternate between). For example: Given binary tree{3,9,20,#,#,15,7}, ...