careercup-树与图 4.8

#include<iostream>
#include<new>
#include<cmath>
using namespace std;

//Definition for binary tree
struct TreeNode
{
    int val;
    TreeNode *left;
    TreeNode *right;
    TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};

void createTree(TreeNode *&root)
{
    int i;
    cin>>i;
    if(i!=0)
    {
        TreeNode *tmp=new TreeNode(i);
        root=tmp;
        createTree(root->left);
        createTree(root->right);
    }
}

bool isSubTree(TreeNode *root1,TreeNode *root2)
{
    //root2为空时是任何数的子树
    if(root2==NULL)
        return true;
    //如果root2不为空，但是root1为空，则返回false
    if(root1==NULL)
        return false;
    if(root1->val==root2->val)
        return isSubTree(root1->left,root2->left)&&isSubTree(root1->right,root2->right);
    else
        return isSubTree(root1->left,root2)||isSubTree(root1->right,root2);
    return false;
}

int main()
{
    TreeNode *root1=NULL;
    TreeNode *root2=NULL;
    createTree(root1);
    createTree(root2);
    cout<<isSubTree(root1,root2)<<endl;
}