krsu 3404 (not my code)

#include "bits/stdc++.h"
using namespace std;

#define ar array
typedef long long ll;

const int N = 1e5 + 5;
int x[N], y[N], z[N];
ll res_pref[N], res_suff[N];

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    int X, Y, Z;
    cin >> X >> Y >> Z;
    int n = X + Y + Z;
    for (int i = 0; i < n; i++) {
        cin >> x[i] >> y[i] >> z[i];
    }
    vector<int> p(n);
    iota(p.begin(), p.end(), 0);
    sort(p.begin(), p.end(),
         [&](int i, int j) { return y[i] - x[i] < y[j] - x[j]; });

    ll ans = 0;
    priority_queue<int> pref, suff;
    for (int i = 0; i < n; i++) {
        if (i)
            res_pref[i] = res_pref[i - 1];
        res_pref[i] += x[p[i]];
        pref.push(z[p[i]] - x[p[i]]);
        if (i >= X) {
            res_pref[i] += pref.top();
            pref.pop();
        }
    }

    for (int i = n - 1; ~i; i--) {
        if (i + 1 < n)
            res_suff[i] = res_suff[i + 1];
        res_suff[i] += y[p[i]];
        suff.push(z[p[i]] - y[p[i]]);
        if (i + Y < n) {
            res_suff[i] += suff.top();
            suff.pop();
        }
    }

    for (int i = X - 1; i + Y < n; i++) {
        ans = max(ans, res_pref[i] + res_suff[i + 1]);
    }

    cout << ans << "\n";
}

/*

1 2 1
2 4 4
3 2 1
7 6 7
5 2 3

*/