啊题解

#include<bits/stdc++.h>
using namespace std;
int main(){
string a, b, c;
cin >> a;
cin >> b;
cin >> c;
string d = a + b;
if(d.find(c) != -1)
cout << c << " is substring of " << a << " and " << b;
else
cout << c << " is not substring of " << a << " and " << b;
return 0;
}