题解

#include<bits/stdc++.h>
using namespace std;

int main()
{
    string a,b,c,d;
    cin >> a >> b >> c;
    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;
}