func_code_string: #include <bits/stdc++.h>   #define ll long long   #define f(n) for(ll i=0;i<n;i++)   #define mod 998244353   #define vl vector<ll>   #define pb push_back   #define mk make_pair   #define forn(i, n) for (int i = 0; i < int(n); i++)   #define nl   n    #define IOS ios_base::sync_with_stdio(false);       #include <iostream>   using namespace std;          void solve()   {           ll n;           cin>>n;           ll a[n];           for(ll i=0;i<n;i++)           {               cin>>a[i];           }           sort(a,a+n);           ll v=0,s=0;               for(int i=2;i<n;i++)           {               s+=a[i-2];               v-=(a[i]*(i-1));               v+=s;           }           cout<<v<<endl;   }          void init_code()   {       #ifndef ONLINE_JUDGE       freopen( input.txt ,  r , stdin);       freopen( output.txt ,  w , stdout);       #endif    }           int main()   {       init_code();      IOS      cin.tie(NULL);      cout.tie(NULL);      ll t;      cin>>t;      //t=1;      while(t--)      {         solve();      }      return 0;   }