1557A - Ezzat and Two Subsequences - CodeForces Solution

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;


#define ElGed_Sevawy  ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ll long long
#define ull unsigned long long
#define ld long double
#define el '\n'
#define pi acos(-1)
#define F first
#define S second
#define sz(x) (int)(x).size()

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

mt19937 gen(chrono::system_clock::now().time_since_epoch().count());
ll rand(ll l, ll r){
    return uniform_int_distribution<ll>(l, r)(gen);
}

const ll N = 2e5 + 5, M = 1e6 + 5, MOD1 = 1e9 + 7, MOD2 = 1e9 + 9, lg = 21, INF  = 2e9, P1 = 29, P2 = 31;

void go() {
    int n;
    cin >> n;
    ll a[n + 2];
    for (int i = 1; i <= n; i++) cin >> a[i];
    sort(a + 1, a + n + 1);
    ll ans = a[n], sum = 0;
    for(int i = 1; i <= n - 1; i++)
        sum += a[i];

    cout << fixed << setprecision(6) << ans + (1.0 * sum / (n - 1)) << el;
}
int32_t main() {
    ElGed_Sevawy
    int tc = 1;
    cin >> tc;
    while (tc--)
        go();
}