剑指Offer16 判断子树

/*************************************************************************
    > File Name: 17_MirrorOfBinaryTree.cpp
    > Author: Juntaran
    > Mail: JuntaranMail@gmail.com
    > Created Time: 2016年08月30日 星期二 17时12分37秒
 ************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#include <bits/stdc++.h>

using namespace std;

// 二叉树结构体
struct TreeNode
{
    int val;
    TreeNode* left;
    TreeNode* right;
};

TreeNode* createTree()
{
    TreeNode* root = (TreeNode*)malloc(sizeof(TreeNode));
    root->val = 8;
    root->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->val = 8;
    root->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->right->val = 7;
    root->right->left = NULL;
    root->right->right = NULL;
    root->left->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->left->val = 9;
    root->left->left->left = NULL;
    root->left->left->right = NULL;
    root->left->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->right->val = 2;
    root->left->right->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->right->left->val = 4;
    root->left->right->left->left = NULL;
    root->left->right->left->right = NULL;
    root->left->right->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->right->right->val = 7;
    root->left->right->right->left = NULL;
    root->left->right->right->right = NULL;
    
    return root;
}

TreeNode* createSubTree()
{
    TreeNode* root = (TreeNode*)malloc(sizeof(TreeNode));
    root->val = 8;
    root->left = (TreeNode*)malloc(sizeof(TreeNode));
    root->left->val = 9;
    root->right = (TreeNode*)malloc(sizeof(TreeNode));
    root->right->val = 2;
    root->left->left = NULL;
    root->left->right = NULL;
    root->right->left = NULL;
    root->right->right = NULL;
    
    return root;
}

bool DoesTree1HaveTree2(TreeNode* root1, TreeNode* root2)
{
    if (root2 == NULL)
        return true;
    if (root1 == NULL)
        return false;
    if (root1->val != root2->val)
        return false;
    
    return DoesTree1HaveTree2(root1->left, root2->left) && DoesTree1HaveTree2(root1->right, root2->right);
}

bool hasSubTree(TreeNode* root1, TreeNode* root2)
{
    int ret = false;
    if (root1!=NULL && root2!=NULL)
    {
        if (root1->val == root2->val)
            ret = DoesTree1HaveTree2(root1, root2);
        if (ret == false)
            ret = hasSubTree(root1->left, root2);
        if (ret == false)
            ret = hasSubTree(root1->right, root2);
    }
}

// 层序遍历二叉树
void PrintTreeByLevel(TreeNode* root)
{
    if (root == NULL)
        return;
    
    vector<TreeNode*> vec;
    vec.push_back(root);
    int cur = 0;
    int last = 1;
    
    while (cur < vec.size())
    {
        last = vec.size();
        while (cur < last)
        {
            printf("%d ", vec[cur]->val);
            if (vec[cur]->left != NULL)
                vec.push_back(vec[cur]->left);
            if (vec[cur]->right != NULL)
                vec.push_back(vec[cur]->right);
            
            ++ cur;
        }
        printf("
");
    }
}

int main()
{
    TreeNode* tree1 = createTree();
    TreeNode* tree2 = createSubTree();
    
    PrintTreeByLevel(tree1);
    printf("
");
    PrintTreeByLevel(tree2);
    printf("
");
    
    bool ret = hasSubTree(tree1, tree2);
    if (ret == true)
        printf("Yes
");
    else
        printf("No
");
    
    return 0;
}