代码

#include<bits/stdc++.h>
using namespace std;
int main(){
	int ok=0;
	string a,b;
	cin>>a>>b;
	int la=a.length(),lb=b.length();
	int t=0;
	if(la<lb){
		swap(la,lb);
		swap(a,b);
		t=1;
	}
	for(int i=0;i<la;i++){
		ok=0;
		for(int j=i;j<j+la;j++){
			if(a[j]!=b[j]){
				ok=1;
				break;
			}
		}
		if(ok==0){
			if(t==0)cout<<b<<" is substring of "<<a;
			else cout<<a<<" is substring of "<<b;
			return 0;
		}
	}
	cout<<"No substring";
	return 0;
}