Submission #1066407

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066407		allin27x	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	848 ms	63600 KiB

tickets

#include <bits/stdc++.h>
using namespace std;
#define int long long

void allocate_tickets(vector<vector<signed>> s);

int find_maximum(signed k, vector<vector<signed>> x) {
    int n = x.size(); int m = x[0].size();
    vector<vector<signed>> s(n, vector<signed>(m,-1));
    vector<stack<int>> pls(n);
    vector<stack<int>> mns(n);
    int ans = 0;

    for (int i=0; i<n; i++) {
        for (int j=0; j<k; j++) {
            mns[i].push(j);
        }
    }
    set<pair<int,int>> ps;
    for (int i=0; i<n; i++) {
        ps.insert({x[i][m - (k-mns[i].top())] + x[i][mns[i].top()],i});
    }

    for (int ct=0; ct<k*n/2; ct++) {
        int i = (*ps.rbegin()).second; ps.erase(*ps.rbegin());
        pls[i].push(m - (k-mns[i].top())); mns[i].pop();
        if (mns[i].empty()) continue;
        ps.insert({x[i][m - (k-mns[i].top())] + x[i][mns[i].top()],i});

    }

    set<pair<int,int>> pl;
    for (int i=0; i<n; i++) pl.insert({pls[i].size(), i});
    vector<int> bg(n, 0);
    for (int rnd = 0; rnd<k; rnd++){
        bg.assign(n,0);
        for (int i=0; i<n/2; i++) {
            bg[(*pl.rbegin()).second] = 1; pl.erase(*pl.rbegin());
        }
        for (int i=0; i<n; i++) {
            if (bg[i]) {
                ans += x[i][pls[i].top()];
                s[i][pls[i].top()]=rnd; pls[i].pop();
                pl.insert({pls[i].size(), i});
            } else {
                ans -= x[i][mns[i].top()];
                s[i][mns[i].top()]=rnd; mns[i].pop();
            }
        }
    }
    allocate_tickets(s);
    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