poj 3753 根据关键字进行字符串拷贝

#include<iostream>
#include<string>
using namespace std;
int main()
{
    string str1,str2;
    while(cin>>str1)
    {
        while(cin>>str2&&str2!="END")
        {
            if(str2=="NULL")
            {
                printf("0 NULL\n");continue;
            }
            int id=str1.find(str2);
            if(id==0)
            {
                printf("0 NULL\n");
            }
            else if(id==-1)
                cout<<str1.size()<<" "<<str1<<endl;
            else
            {
                cout<<id<<" ";
                for(int i=0;i<id;++i)
                    cout<<str1[i];
                cout<<endl;
            }
        }
    }
    return 0;
}