剑指offer——树的镜像

题目描述：操作给定的二叉树，将其变换为源二叉树的镜像。

输入描述：

二叉树的镜像定义：源二叉树 
    	    8
    	   /  \
    	  6   10
    	 / \  / \
    	5  7 9 11
    	镜像二叉树
    	    8
    	   /  \
    	  10   6
    	 / \  / \
    	11 9 7  5

C++代码： 

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* tmp = NULL;
		tmp = pRoot->left;
		pRoot->left = pRoot->right;
		pRoot->right = tmp;
		if (pRoot->left != NULL)Mirror(pRoot->left);
		if (pRoot->right != NULL)Mirror(pRoot->right);
    }
};