Submission #670418

#	Time	Username	Problem	Language	Result	Execution time	Memory
670418		CatalinT	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	795 ms	76224 KiB

tickets

#include <vector>
#include <iostream>
#include <cassert>
#include <algorithm>
#include <numeric>
#include <iostream>
#include <set>
#include <map>
#include <string>
#include <unordered_map>
#include <functional>
#include <bitset>
#include <sstream>
#include <queue>

#include "tickets.h"

using namespace std;

using int64 = long long;

// void allocate_tickets(std::vector<std::vector<int>> _d) {
// }

struct Swap {
    int64 gain;
    int row;
    int l;
    int r;

    bool operator < (const Swap& other) const {
        if (gain != other.gain)
            return gain > other.gain;
        return row < other.row;
    }
};

long long find_maximum(int K, vector<vector<int>> D) {
    int N = D.size();
    int M = D[0].size();

    set<Swap> cand;

    int64 cur = 0;

    vector<vector<int>> assig(N, vector<int>(M, -1));

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < K; j++) {
            cur += (-D[i][j]);
        }
        cand.insert(Swap{D[i][M-1] + D[i][K-1], i, K - 1, M - 1});
    }

    vector<int> deg(N);

    for (int steps = 0; steps < K * N / 2; steps++) {
        auto el = *cand.begin();
        cand.erase(cand.begin()); 
    
        cur += el.gain;

        deg[el.row]++;

        if (el.l >= 1) {
            el.l--;
            el.r--;
            el.gain = D[el.row][el.r] + D[el.row][el.l]; 
            cand.insert(el);
        }
    }

    auto old_deg = deg;

    priority_queue<pair<int, int>> heap;

    for (int i = 0; i < N; i++) {
        heap.push({deg[i], i});
    }

    for (int r = 0; r < K; r++) {
        // Assign N / 2 to the largest
        vector<pair<int, int>> put_back;
        vector<char> used(N);

        for (int i = 0; i < N / 2; i++) {
            auto el = heap.top();
            heap.pop();

            assig[el.second][M - 1 - (el.first - 1)] = r;

            assert(!used[el.second]);
            used[el.second] = true;

            el.first--;
            put_back.push_back(el);
        }

        for (auto el : put_back)
            heap.push(el);
    }

    for (int i = 0; i < N; i++) {
        old_deg[i] = K - old_deg[i];
        vector<char> used(K);
        for (int j = 0; j < M; j++) {
            if (assig[i][j] != -1) {
                used[assig[i][j]] = 1;
            }
        }
        int k = 0;
        for (int j = 0; j < old_deg[i]; j++) {
            while (used[k])
                k++;
            assig[i][j] = k;
            used[k] = 1;
        }
    }

    // for (int k = 0; k < K; k++) {
    //     cerr << "round: " << k << "\n";
    //     for (int i = 0; i < N; i++) {
    //         for (int j = 0; j < M; j++) {
    //             if (assig[i][j] == k) {
    //                 cerr << i << ", " << j << " = " << D[i][j] << "\n";
    //             }
    //         }
    //     }
    // }

    allocate_tickets(assig);

    return cur;
}

// int main() {
//     ios_base::sync_with_stdio(false);
//     cin.tie(NULL);

//     // int N, M, K;
//     // cin >> N >> M >> K;

//     // vector<vector<int>> D(N, vector<int>(M));

//     // for (int i = 0; i < N; i++) {
//     //     for (int j = 0; j < M; j++) {
//     //         cin >> D[i][j];
//     //     }
//     // }

//     // cerr << find_maximum(K, D) << "\n";

//     //cerr << find_maximum(2, {{0, 2, 5},{1, 1, 3}}) << "\n";
//     //cerr << find_maximum(1, {{5, 9}, {1, 4}, {3, 6}, {2, 7}}) << "\n";

//     return 0;
// }

• 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