剑指 offer 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;
        }
        TreeNode *temp ;
        temp =  pRoot->left;
        pRoot->left =  pRoot->right;
        pRoot->right = temp;
        if(pRoot->left!=NULL){
            Mirror(pRoot->left);
        }
        if ( pRoot->right!=NULL){
            Mirror(pRoot->right);
        }
    }
};