LeetCode-二叉树的镜像

二叉树的镜像

二叉树的镜像

1. 给定一个二叉树，输出二叉树的镜像。
2. 只需要使用一个简单的递归，分别对左右子树反转后再对当前结点进行反转。

#include<iostream>
#include<cstring>
#include<string>
#include<algorithm>
#include<cstdio>
#include<queue>
#include<vector>
using namespace std;
// Definition for a binary tree node.
struct TreeNode {
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
//      4
//    /   \
//   2     7
//  / \   / \
// 1   3 6   9
class Solution {
public:
    void reverse(TreeNode* node){
        if(node->left){
            reverse(node->left);
        }
        if(node->right){
            reverse(node->right);
        }
        TreeNode* temp=node->left;
        node->left=node->right;
        node->right=temp;
    }
    TreeNode* mirrorTree(TreeNode* root) {
        if(root)//root不为null
            reverse(root);
        return root;
    }
};
int main(){
    TreeNode* t1=new TreeNode(1);
    TreeNode* t2=new TreeNode(2);
    TreeNode* t3=new TreeNode(3);
    TreeNode* t4=new TreeNode(4);
    TreeNode* t6=new TreeNode(6);
    TreeNode* t7=new TreeNode(7);
    TreeNode* t9=new TreeNode(9);
    t7->left=t6;t7->right=t9;
    t2->left=t1;t2->right=t3;
    t4->left=t2;t4->right=t7;
    Solution solution;
    TreeNode* root=solution.mirrorTree(t4);
    cout<<root->left->val<<" "<<root->right->val<<endl;
    system("pause");
    return 0;
}