遍历树中的所有点,每次遍历完之后把左右儿子swap一下。
/**
* 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 mirror(TreeNode* root) {
if (!root) return ;
mirror(root->left);
mirror(root->right);
swap(root->left, root->right);
}
};