Leetcode 226 Invert Binary Tree 二叉树

/**
* 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:
void swapLR(TreeNode* root){
if(!root) return;
else{
TreeNode *t = root->left;
root->left = root->right;
root->right = t;
swapLR(root->left);
swapLR(root->right);
}

}
TreeNode* invertTree(TreeNode* root) {
swapLR(root);
return root;
}
};