func_code_string: #include <bits/stdc++.h>   #include <time.h>   using namespace std;      #define ll long long   #define ld long double   #define precision(x,d) cout<<fixed<<setprecision(d)<<x   #define all(x) x.begin(),x.end()   #define IOS ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);srand(time(NULL));   #define MOD 1000000007   #define INF LONG_LONG_MAX   #define NINF LONG_LONG_MIN   #define endl   n    #define yes cout<< YES <<endl   #define no cout<< NO <<endl   #define db4(x,y,z,k) cout<<#x<<  :  <<x<<  t <<#y<<  :  <<y<<  t <<#z<<  :  <<z<<  t <<#k<<  :  <<k<<endl;      int main()   {       IOS;       ll t,n,m,k,u,v,x,y;       t=1;       cin >> t;       while(t--)       {           cin >> n;           vector<ll> a(n);           for(int i=0;i<n;i++)               cin >> a[i];           sort(all(a));           ll ans = 0;           for(int i=1;i<n;i++)           {               m = i;               ans -= m*a[i];               k = (n-i-1);               ans += k*a[i];           }           ans += a[n-1];           cout << ans << endl;       }       return 0;   }   