1632A - ABC - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
int main()
{

    int t;
    cin >> t;
    while (t--)
    {

        int n;
        cin >> n;
        string s;
        cin >> s;
        if (n == 2 && (s=="01"||s=="10"))
        {
           cout<<"YES"<<endl;
        }
        else if (n == 1)
            cout << "YES" << endl;
        else
            cout << "NO" << endl;
    }
}