【Invert Binary Tree】cpp

標籤：

題目：

Invert Binary Tree Total Accepted: 20346 Total Submissions: 57084My SubmissionsQuestion Solution 

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 tree on a whiteboard so fuck off.

代碼：

/** * Definition for a binary tree node. * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    TreeNode* invertTree(TreeNode* root) {            if ( !root ) return root;            TreeNode* tmp = root->left;            root->left = Solution::invertTree(root->right);            root->right = Solution::invertTree(tmp);            return root;    }};

tips：

翻轉二叉樹跟交換兩個int差不多。。。重點是留一個tmp。

【Invert Binary Tree】cpp