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 ret…

从上往下打印二叉树这个是不分行的,用一个队列就可以实现 class Solution { public: vector<int> PrintFromTopToBottom(TreeNode* root) { vector<int> result; queue<TreeNode* > container; if(root == NULL) return result; container.push(root); ){ TreeNode* rot = container.f…

// 103. Binary Tree Zigzag Level Order Traversal // https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/description/ // swift // Definition for a binary tree node. public class TreeNode { public var val: Int public var left: TreeNo…

Binary Tree Zigzag Level Order Traversal 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,#…

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…

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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…

题目来源 https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/ 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). 题意分…

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…

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…

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    /  \  …

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…

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…

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,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its…

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,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its…

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…

给定一个二叉树,返回其节点值的锯齿形层次遍历.(即先从左往右,再从右往左进行下一层遍历,以此类推,层与层之间交替进行).例如:给定二叉树 [3,9,20,null,null,15,7],    3   / \  9  20    /  \   15   7返回锯齿形层次遍历如下:[  [3],  [20,9],  [15,7]]详见:https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/description…

相对于102题,稍微改变下方法就行 迭代方法: 在102题的基础上,加上一个变量来判断是不是需要反转 反转的话,当前list在for循环结束后用collection的反转方法就可以实现反转 递归方法: 由于有层数,所以用层数%2判断是不是需要反转 反转的话就元素都添加到最前边,一层添加完后就是反的 下边是递归方法 List<List<Integer>> res = new ArrayList<>(); public List<List<Integer>…

▶ 有关将一棵二叉树转化为二位表的题目,一模一样的套路出了四道题 ▶ 第 102 题,简单的转化,[ 3, 9, 20, null, null, 15, 7 ] 转为 [ [ 15, 7 ] , [ 9, 20 ] , [ 3 ] ] ● 自己的代码,6 ms,先根序遍历,最快的解法算法与之相同 class Solution { public: void visit(TreeNode* root, vector<vector<int>>& table, int level)…

原题链接 题目要求以"Z"字型遍历二叉树,并存储在二维数组里. 利用BFS,对每一层进行遍历.对于每一层是从左还是从右,用一个整数型判断当前是偶数行还是奇数行就可以了. class Solution { public: vector<vector<int>> res; vector<vector<int>> zigzagLevelOrder(TreeNode *root) { if (root == NULL) return res; s…

原题地址 基本数据结构操作,二叉树的层次遍历. 代码: vector<vector<int> > zigzagLevelOrder(TreeNode *root) { vector<vector<int> > res; vector<TreeNode *> layer; bool l2r = true; layer.push_back(root); while (!layer.empty()) { vector<TreeNode *>…

103. 二叉树的锯齿形层次遍历 103. Binary Tree Zigzag Level Order Traversal 题目描述 给定一个二叉树,返回其节点值的锯齿形层次遍历.(即先从左往右,再从右往左进行下一层遍历,以此类推,层与层之间交替进行). LeetCode103. Binary Tree Zigzag Level Order Traversal中等 例如: 给定二叉树 [3,9,20,null,null,15,7], 3 / \ 9 20 / \ 15 7 返回锯齿形层次遍历如…

题目描述: Binary Tree Zigzag Level Order Traversal AC Rate: 399/1474 My Submissions 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).…

Binary Tree Zigzag Level Order Traversal 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,#…

Binary Tree Zigzag Level Order Traversal 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,…

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…

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…

Binary Tree Zigzag Level Order Traversal [LeetCode] https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/ Total Accepted: 44275 Total Submissions: 165753 Difficulty: Medium Question Given a binary tree, return the zigzag level order…

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,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its…

题目 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,#,#,15,7}, return its zigzag level ord…