剑指Offer17 二叉树的镜像

Posted 2020-08-05 Juntaran

  1 /*************************************************************************
  2     > File Name: 17_MirrorOfBinaryTree.cpp
  3     > Author: Juntaran
  4     > Mail: [email protected]
  5     > Created Time: 2016年08月30日 星期二 17时10分03秒
  6  ************************************************************************/
  7 
  8 #include <stdio.h>
  9 #include <stdlib.h>
 10 #include <malloc.h>
 11 #include <bits/stdc++.h>
 12 
 13 using namespace std;
 14 
 15 // 二叉树结构体
 16 struct TreeNode
 17 {
 18     int val;
 19     TreeNode* left;
 20     TreeNode* right;
 21 };
 22 
 23 TreeNode* createTree()
 24 {
 25     TreeNode* root = (TreeNode*)malloc(sizeof(TreeNode));
 26     root->val = 8;
 27     root->left = (TreeNode*)malloc(sizeof(TreeNode));
 28     root->left->val = 8;
 29     root->right = (TreeNode*)malloc(sizeof(TreeNode));
 30     root->right->val = 7;
 31     root->right->left = NULL;
 32     root->right->right = NULL;
 33     root->left->left = (TreeNode*)malloc(sizeof(TreeNode));
 34     root->left->left->val = 9;
 35     root->left->left->left = NULL;
 36     root->left->left->right = NULL;
 37     root->left->right = (TreeNode*)malloc(sizeof(TreeNode));
 38     root->left->right->val = 2;
 39     root->left->right->left = (TreeNode*)malloc(sizeof(TreeNode));
 40     root->left->right->left->val = 4;
 41     root->left->right->left->left = NULL;
 42     root->left->right->left->right = NULL;
 43     root->left->right->right = (TreeNode*)malloc(sizeof(TreeNode));
 44     root->left->right->right->val = 7;
 45     root->left->right->right->left = NULL;
 46     root->left->right->right->right = NULL;
 47     
 48     return root;
 49 }
 50 
 51 void Mirror(TreeNode* root)
 52 {
 53     if (root == NULL)
 54         return;
 55     if (root->left==NULL && root->right==NULL)
 56         return;
 57     
 58     TreeNode* temp = root->left;
 59     root->left = root->right;
 60     root->right = temp;
 61     
 62     if (root->left)
 63         Mirror(root->left);
 64     if (root->right)
 65         Mirror(root->right);
 66 }
 67 
 68 // 层序遍历二叉树
 69 void PrintTreeByLevel(TreeNode* root)
 70 {
 71     if (root == NULL)
 72         return;
 73     
 74     vector<TreeNode*> vec;
 75     vec.push_back(root);
 76     int cur = 0;
 77     int last = 1;
 78     
 79     while (cur < vec.size())
 80     {
 81         last = vec.size();
 82         while (cur < last)
 83         {
 84             printf("%d ", vec[cur]->val);
 85             if (vec[cur]->left != NULL)
 86                 vec.push_back(vec[cur]->left);
 87             if (vec[cur]->right != NULL)
 88                 vec.push_back(vec[cur]->right);
 89             
 90             ++ cur;
 91         }
 92         printf("\n");
 93     }
 94 }
 95 
 96 int main()
 97 {
 98     TreeNode* tree = createTree();
 99     
100     PrintTreeByLevel(tree);
101     printf("\n");
102     
103     Mirror(tree);
104     PrintTreeByLevel(tree);
105     
106     return 0;
107 }