Submission #704629

#	Time	Username	Problem	Language	Result	Execution time	Memory
704629		bebra	Carnival Tickets (IOI20_tickets)	C++17	27 / 100	3059 ms	51664 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
 
#define dbg(x) cerr << #x << ": " << x << endl;
 
 
ll find_maximum(int k, vector<vector<int>> x) {
    int n = x.size();
    int m = x[0].size();

    vector<vector<int>> res(n, vector<int>(m, -1));
    vector<set<int>> minus_sign(n), plus_sign(n);
    vector<int> plus_cnt(n);

    priority_queue<pair<int, int>> pq;

    vector<int> first(n, k - 1);
    vector<int> last(n, m - 1);

    ll ans = 0;
    for (int i = 0; i < n; ++i) {
        pq.emplace(x[i][first[i]] + x[i][last[i]], i);
        for (int j = 0; j < k; ++j) {
            minus_sign[i].insert(j);
            ans -= x[i][j];
        }
    }

    for (int t = 0; t < n * k / 2; ++t) {
        auto [value, i] = pq.top();
        pq.pop();
        ans += value;

        ++plus_cnt[i];
        plus_sign[i].insert(last[i]);
        minus_sign[i].erase(first[i]);

        if (first[i] > 0) {
            --first[i];
            --last[i];
            pq.emplace(x[i][first[i]] + x[i][last[i]], i);
        }
    }

    for (int t = 0; t < k; ++t) {
        vector<int> p(n);
        iota(p.begin(), p.end(), 0);
        sort(p.begin(), p.end(), [&](int lhs, int rhs) {
            return plus_cnt[lhs] < plus_cnt[rhs];
        });

        for (int i = 0; i < n / 2; ++i) {
            res[p[i]][*minus_sign[p[i]].begin()] = t;
            minus_sign[p[i]].erase(minus_sign[p[i]].begin());
        }
        for (int i = n / 2; i < n; ++i) {
            res[p[i]][*plus_sign[p[i]].begin()] = t;
            plus_sign[p[i]].erase(plus_sign[p[i]].begin());
            --plus_cnt[i];
        }
    }
    
    allocate_tickets(res);
    return ans;
}
 
 
// int main() {
 //    int n, m, k;
 //    cin >> n >> m >> k;
 
 //    vector<vector<int>> a(n, vector<int>(m));
 //    for (int i = 0; i < n; ++i) {
 //        for (int j = 0; j < m; ++j) {
 //            cin >> a[i][j];
 //        }
 //    }
 
 //    cout << find_maximum(k, a) << '\n';
// }


/*
4 3 2
0 3 4 
0 0 2 
1 2 4 
0 4 4 

right:
15
*/

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 0 / 14
• Subtask 4: 0 / 14
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23
• Subtask 7: 0 / 10