Submission #471465

#	Time	Username	Problem	Language	Result	Execution time	Memory
471465		ljuba	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	1226 ms	121020 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>

typedef long long ll;
using namespace std;

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

    priority_queue<pair<ll, pair<int, int>>> pq;

    for(int i = 0; i < n; ++i) {
        for(int j = 0; j < k; ++j) {
            ans -= x[i][j];
            znak[i][j] = -1;
            int ind = k-1-j;
            ind = m-1-ind;
            ll dodaj = x[i][j] + x[i][ind];
            pq.push({dodaj, {i, j}});
        }
    }

    for(int uradi = 0; uradi < n*k/2; ++uradi) {
        auto tren = pq.top();
        ans += tren.first;
        pair<int, int> mesto = tren.second;
        pq.pop();

        znak[mesto.first][mesto.second] = 0;
        int ind = k-1-mesto.second;
        ind = m-1-ind;
        znak[mesto.first][ind] = 1;
    }

    vector<stack<int>> minus(n), plus(n);

    for(int i = 0; i < n; ++i) {
        for(int j = 0; j < m; ++j) {
            if(znak[i][j] == -1) {
                minus[i].push(j);
            } else if(znak[i][j] == 1) {
                plus[i].push(j);
            }
        }
    }

    //for(int i = 0; i < n; ++i) {
        //for(int j = 0; j < m; ++j) {
            //cerr << znak[i][j] << " ";
        //}
        //cerr << endl;
    //}

    vector<vector<int>> odg(n, vector<int>(m, -1));

    for(int uradi = 0; uradi < k; ++uradi) {
        vector<bool> marked(n, false);
        vector<bool> plusici, minusici;
        plusici = marked;
        minusici = marked;
        for(int i = 0; i < n; ++i) {
            if(!minus[i].empty()) {
                minusici[i] = true;
            }
            if(!plus[i].empty()) {
                plusici[i] = true;
            }
        }

        vector<int> moraPlus, moraMinus;

        for(int i = 0; i < n; ++i) {
            if(plusici[i] && !minusici[i]) {
                moraPlus.push_back(i);
            }
            if(minusici[i] && !plusici[i]) {
                if((int)moraMinus.size() < n/2) {
                    marked[i] = true;
                }
                moraMinus.push_back(i);
            }
        }

        for(int i = 0; i < n && (int)moraMinus.size() < n/2; ++i) {
            if(marked[i])
                continue;
            if(!minus[i].empty()) {
                marked[i] = true;
                moraMinus.push_back(i);
            }
        }

        for(int i = 0; i < n; ++i) {
            if(marked[i]) {
                odg[i][minus[i].top()] = uradi;
                minus[i].pop();
            } else {
                odg[i][plus[i].top()] = uradi;
                plus[i].pop();
            }
        }
    }

    allocate_tickets(odg);
    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