LeetCode226. Invert Binary Tree

Invert a binary tree.

4
/   \
2     7
/ \   / \
1   3 6   9

to

4
/   \
7     2
/ \   / \

9 6 3 1解法：TreeNode* invertTree(TreeNode* root) {if(root==NULL)return NULL;TreeNode *temp;temp=root->left;root->left=temp;root->right=temp;invertTree(root->right);invertTree(root->left);return root;}