/*
Invert a binary tree.
4
/ \
27
/ \ / \
1369to4
/ \
72
/ \ / \
9631
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.
*/
/**
* 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=root->right;
root->right=tmp;
invertTree(root->left);
invertTree(root->right);
return root;
}
};