MAXSUMSQ - LQDOJ

//Make CSP great again
#include <bits/stdc++.h>
#define TASK "TESTCODE"
using namespace std;
const int N = 1e5;
int a[N + 1], n, q, s;
multiset<int> Multiset;
long long sumsquare = 0, sumnum = 0;
long long Square(int u)
{
    return 1LL * u * u;
}
void read()
{
   cin >> n >> s;
   for (int i = 1; i <= n; ++ i)
   {
       cin >> a[i];
       Multiset.insert(a[i]);
       sumsquare += Square(a[i]);
       sumnum += a[i];
   }
}
long long Answer()
{
    long long big = *Multiset.rbegin();
    return sumsquare - Square(big) + Square(big + s - sumnum);
}
void solve()
{
   cout << Answer() << '\n';
   cin >> q;
   while (q--)
   {
       int i, x;
       cin >> i >> x;
       sumsquare = sumsquare - Square(a[i]) + Square(x);
       sumnum = sumnum - a[i] + x;
       auto it = Multiset.find(a[i]);
       Multiset.erase(it);
       Multiset.insert(x);
       a[i] = x;
       cout << Answer() << '\n';
   }
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    //freopen(TASK".INP", "r", stdin);
    //freopen(TASK".OUT", "w", stdout);
    int t = 1;
    bool typetest = false;
    if (typetest)
    {
        cin >> t;
    }
    for (int __ = 1; __ <= t; ++ __)
    {
        cerr << "Case " << __ << ":" << '\n';
        read();
        solve();
    }
}