题目 翻转一棵二叉树 您在真实的面试中是否遇到过这个题? Yes 样例 1 1 / \ / \ 2 3 => 3 2 / \ 4 4 和前序遍历代码很相似从叶子节点依次翻转递归到根节点C++代码 void invertBinaryTree(TreeNode* root) { stack<TreeNode*> s; TreeNode* p = root; while (p || !s.empty()) { while (p) { s.push(p); p = p->left; } T…

Invert a binary tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 Trivia: This problem was inspired by this original tweet by Max Howell: Google: 90% of our engineers use the software you wrote (Homebrew), but you can’t invert a binary tre…

题目: 翻转二叉树 翻转一棵二叉树 样例 1 1 / \ / \ 2 3 => 3 2 / \ 4 4 挑战 递归固然可行,能否写个非递归的? 解题: 递归比较简单,非递归待补充 Java程序: /** * Definition of TreeNode: * public class TreeNode { * public int val; * public TreeNode left, right; * public TreeNode(int val) { * this.val = val;…

Invert a binary tree. Example: Input: 4 / \ 2 7 / \ / \ 1 3 6 9 Output: 4 / \ 7 2 / \ / \ 9 6 3 1 Trivia:This problem was inspired by this original tweet by Max Howell: Google: 90% of our engineers use the software you wrote (Homebrew), but you can’t…

翻转二叉树的步骤: 1.翻转根节点的左子树(递归调用当前函数) 2.翻转根节点的右子树(递归调用当前函数) 3.交换根节点的左子节点与右子节点 class Solution{ public: void exchage(TreeNode *root){ TreeNode* node=root; if (node!=NULL){ TreeNode* temp=node->left; node ->left=node->right; node->right=temp; } } TreeN…

Given n points on a 2D plane, find the maximum number of points that lie on the same straight line. Example Given 4 points: (1,2), (3,6), (0,0), (1,3). The maximum number is 3. LeeCode上的原题,可参见我之前的博客Invert Binary Tree 翻转二叉树. 解法一: // Recursion class So…

翻转一棵二叉树. 示例: 输入: 4 / \ 2 7 / \ / \ 1 3 6 9 输出: 4 / \ 7 2 / \ / \ 9 6 3 1 备注: 这个问题是受到 Max Howell的 原问题 启发的 : 谷歌:我们90%的工程师使用您编写的软件(Homebrew),但是您却无法在面试时在白板上写出翻转二叉树这道题,这太糟糕了. # Definition for a binary tree node. # class TreeNode: # def __init__(self, x):…

LeetCode:翻转二叉树[226] 题目描述 翻转一棵二叉树. 示例: 输入: 4 / \ 2 7 / \ / \ 1 3 6 9 输出: 4 / \ 7 2 / \ / \ 9 6 3 1 题目分析 略. Java题解 /** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val…

翻转一棵二叉树. 示例: 输入: 4 / \ 2 7 / \ / \ 1 3 6 9 输出: 4 / \ 7 2 / \ / \ 9 6 3 1 备注:这个问题是受到 Max Howell的 原问题 启发的 : 谷歌:我们90%的工程师使用您编写的软件(Homebrew),但是您却无法在面试时在白板上写出翻转二叉树这道题,这太糟糕了. 这道题比较简单,就是一路判断下去就是了.注意在二叉树为空,或者左右节点为空时做个特判. 代码如下: class Solution { public TreeNod…

题目:翻转二叉树,例如 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 已知二叉树的节点定义如下: class TreeNode { int val; TreeNode left; TreeNode right; TreeNode(int x) { val = x; } } 分析:该题有个小故事:Google: 90% of our engineers use the software you wrote (Homebrew), bu…