==code(cpp)|
//Cristian Lambru
#include<iostream>

#include<cstdio>

#include<vector>
using namespace std;

int main()
{

    int T;
    cin >> T;

    citire();
    parcurgere(0);

    for(int i=1;i<=T;i++)
    {
        citire();
        parcurgere(0);
 
        cout << Suma/((ld)N*(N-1)/2) << "\n";
        sterge();
    }

    cout << Suma/((ld)N*(N-1)/2);

}
==