题解

#include<iostream>
#include<string>
using namespace std;
int main(){
    string s1,s2;
    cin>>s1>>s2;
    if(s2.find(s1)!=string::npos){
        cout<<s1<<" is substring of "<<s2;
    }else if(s1.find(s2)!=string::npos){
        cout<<s2<<" is substring of "<<s1;
    }else{
        cout<<"No substring";
    }
	return 0;
}