二叉树的镜像

操作给定的二叉树，将其变换为源二叉树的镜像。

/*

struct TreeNode {

    int val;

    struct TreeNode *left;

    struct TreeNode *right;

    TreeNode(int x) :

            val(x), left(NULL), right(NULL) {

    }

};*/

class Solution {

public:

    TreeNode* Mirror(TreeNode *pRoot) {

        if(pRoot==NULL)

            returnNULL;

        TreeNode* left=Mirror(pRoot->left);

        TreeNode* right=Mirror(pRoot->right);

        pRoot->left=right;

        pRoot->right=left;

        returnpRoot;

    }

};