class Solution {
public:
    void swap(TreeNode *pRoot)
    {
        TreeNode *temp;
        temp = pRoot->left;
        pRoot->left = pRoot->right;
        pRoot->right = temp;
    }
    void Mirror(TreeNode *pRoot) 
    {
        if(pRoot == NULL) return;
        swap(pRoot);
        Mirror(pRoot->left);
        Mirror(pRoot->right);
    }
};