二叉树镜像

//在牛客上变成通过/*struct TreeNode {    int val;    struct TreeNode *left;    struct TreeNode *right;    TreeNode(int x) :            val(x), left(NULL), right(NULL) {    }};*/class Solution {public:    void Mirror(TreeNode *pRoot) {        if(pRoot !=NULL)        {           TreeNode *temp = pRoot->left;           pRoot->left = pRoot->right;           pRoot->right = temp;           Mirror(pRoot->left);           Mirror(pRoot->right);        }else            return;    }};