Submission #930815

#	Time	Username	Problem	Language	Result	Execution time	Memory
930815		JooDdae	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	782 ms	76220 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

ll find_maximum(int k, vector<vector<int>> x) {
    int n = x.size();
    int m = x[0].size();

    ll ans = 0;
    priority_queue<array<int, 2>> pq;
    vector<int> c(n, 0);
    for(int i=0;i<n;i++) {
        for(int j=0;j<k;j++) ans -= x[i][j];
        pq.push({x[i][m-1]+x[i][k-1], i});
    }

    for(int i=0;i<n*k/2;i++) {
        auto [C, u] = pq.top(); pq.pop();
        ans += C;
        if(++c[u] == k) continue;
        pq.push({x[u][m-1-c[u]]+x[u][k-1-c[u]], u});
    }
    while(!pq.empty()) pq.pop();


    vector<int> L(n, 0), R(n, 0);
    for(int i=0;i<n;i++) R[i] = m-c[i];
    for(int i=0;i<n;i++) c[i] = k-c[i], pq.push({c[i], i});

    vector<vector<int>> re(n, vector<int>(m, -1));
    for(int i=0;i<k;i++) {
        set<int> s;
        for(int j=0;j<n/2;j++) s.insert(pq.top()[1]), pq.pop();

        for(int j=0;j<n;j++) {
            if(s.count(j)) re[j][L[j]++] = i;
            else re[j][R[j]++] = i;
        }

        for(auto x : s) pq.push({--c[x], x});
    }


    allocate_tickets(re);
    return ans;
}

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