func_code_string: #pragma GCC optimize(2)   #include <bits/stdc++.h>   #define all(n) (n).begin(), (n).end()   #define se second   #define fi first   #define pb push_back   #define mp make_pair   #define sqr(n) (n) * (n)   #define rep(i, a, b) for (int i = (a); i <= (b); ++i)   #define per(i, a, b) for (int i = (a); i >= (b); --i)   #define IOS ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr)   using namespace std;   typedef long long ll;   typedef unsigned long long ull;   typedef pair<int, int> PII;   typedef pair<ll, ll> PLL;   typedef vector<int> VI;   typedef double db;       template<class T1, class T2> bool umin(T1& a, T2 b) { return a > b ? (a = b, true) : false; }   template<class T1, class T2> bool umax(T1& a, T2 b) { return a < b ? (a = b, true) : false; }   template<class T> void clear(T& a) { T().swap(a); }       const int N = 2e5 + 5;       int n, m, _, k;   ll a[N];       int main() {    IOS;    for (cin >> _; _; --_) {     cin >> n; ll mx = -1, s = 0;           rep (i, 1, n) cin >> a[i], umax(mx, a[i]), s += a[i];           ll ans = mx * (n - 1ll) - s;           if (ans < 0) ans = (ans % (n - 1) + (n - 1)) % (n - 1);           cout << ans <<   n ;       }    return 0;   }