C

#include <iostream>
#include <cmath>
#include <vector>
#include <queue>
#include <algorithm>
#include <string>
#include <stack>
#include <set>
#include <map>
#define pii pair <int, int>
#define pb(x) push_back(x)
using namespace std;
using ll = long long;
using ld = long double;
using db = double;
void cv(vector <int> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}

void cvl(vector <ll> &v) {
    for (auto x : v) cout << x << ' ';
    cout << "\n";
}


void cvv(vector <vector <int> > &v) {
    for (auto x : v) cv(x);
    cout << "\n";
}

void cvb(vector <bool> v) {
    for (bool x : v) cout << x << ' ';
    cout << "\n";
}

void cvs(vector <string>  v) {
    for (auto a : v) {
        cout << a << "\n";
    }
}

void cvp(vector <pii> a) {
    for (auto p : a) {
        cout << p.first << ' ' << p.second << "\n";
    }
    cout << "\n";
}

#include <ctime>

void gen() {
    int n = rand() % 6 + 3;
    vector <int> a(n);
    for (int i = 0; i < n; ++i) {
        a[i] = rand() % 100;
    }
    cv(a);
}

bool random = 0;
int inf = 2e9;

int my(int n, vector <int> a) {

    int r1, r2, ans;
    r1 = (a[n - 1] - a[n - 2]) + (a[n - 1] - a[0]);
    r2 = (a[1] - a[0]) + (a[n - 1] - a[0]);
    ans = max(r1, r2);
    return ans;
}

int dull(int n, vector <int> a) {
    int rbg, rsm, ans;
    do {
        int rbg = inf;
        for (int i = 0; i <= n - 3; ++i) {
            for (int j = i + 1; j <= n - 2; ++j) {

            }
        }
    } while (next_permutation(a.begin(), a.end()));
    return ans;
}


int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    srand(time(0));
    //gen();
    int t; cin >> t;
    for (int go = 0; go < t; ++go) {
        int n; cin >> n;
        vector <int> a(n);
        for (int &i: a) cin >> i;
        sort(a.begin(), a.end());
        int ans = my(n, a);
        cout << ans << "\n";
    }
}