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