Submission #370661

#	Time	Username	Problem	Language	Result	Execution time	Memory
370661		mihai145	Travelling Merchant (APIO17_merchant)	C++14	0 / 100	47 ms	2668 KiB

merchant

//
// Created by mihai145 on 24.02.2021.
//

#include <iostream>
#include <vector>
#include <queue>

using namespace std;

const int NMAX = 100;
const int KMAX = 1000;
const long long INF = 1e15;

int N, M, K;
int buy[NMAX + 2][KMAX + 2], sell[NMAX + 2][KMAX + 2];

int bestProfit[NMAX + 2][NMAX + 2];
long long minTime[NMAX + 2][NMAX + 2];

void CalcBestProfit() {
    for (int i = 1; i <= N; i++) {
        for (int j = 1; j <= N; j++) {
            if (i != j) {
                //bestProfit[i][j] = 0;
                for (int k = 1; k <= K; k++) {
                    if (sell[j][k] != -1 && buy[i][k] != -1) {
                        bestProfit[i][j] = max(bestProfit[i][j], sell[j][k] - buy[i][k]);
                    }
                }
            }
        }
    }
}

void CalcMinTime() {
    for (int k = 1; k <= N; k++) {
        for (int i = 1; i <= N; i++) {
            for (int j = 1; j <= N; j++) {
                    if(minTime[i][k] != INF && minTime[k][j] != INF)
                        minTime[i][j] = min(minTime[i][j], minTime[i][k] + minTime[k][j]);
            }
        }
    }
}

vector<pair<int, long long>> g[NMAX + 2];
long long cost[NMAX + 2];
int impr[NMAX + 2];
bool inQ[NMAX + 2];

bool MoreThan(long long R) {
    for (int i = 1; i <= N; i++) {
        g[i].clear();
        cost[i] = INF;
        impr[i] = 0;
        inQ[i] = false;

        for (int j = 1; j <= N; j++) {
            g[i].push_back({j, -bestProfit[i][j] + R * minTime[i][j]});
        }
    }

    queue<int> q;
    q.push(1);
    cost[1] = 0;
    inQ[1] = true;

    while (!q.empty()) {
        int node = q.front();
        q.pop();
        inQ[node] = false;

        for (auto it : g[node]) {
            if (cost[it.first] > cost[node] + it.second) {
                cost[it.first] = cost[node] + it.second;

                if (!inQ[it.first]) {
                    q.push(it.first);
                    inQ[it.first] = true;

                    impr[it.first]++;
                    if (impr[it.first] > N) {
                        return true; ///NEGATIVE COST CYCLE
                    }
                }
            }
        }
    }

    return false;
}

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

    cin >> N >> M >> K;

    for (int i = 1; i <= N; i++) {
        for (int j = 1; j <= K; j++) {
            cin >> buy[i][j] >> sell[i][j];
        }
    }

    for (int i = 1; i <= N; i++) {
        for (int j = 1; j <= N; j++) {
            minTime[i][j] = INF;
        }
    }
    for (int i = 1; i <= M; i++) {
        int u, v, t;
        cin >> u >> v >> t;
        minTime[u][v] = t;
    }

    CalcBestProfit();
    CalcMinTime();

    /*
    cout << "BEST PROFIT\n";
    for(int i = 1; i <= N; i++) {
        for(int j = 1; j <= N; j++) {
            cout << bestProfit[i][j] << "   ";
        }
        cout << '\n';
    }
    cout << "\n\n\n";

    cout << "MIN TIME\n";
    for(int i = 1; i <= N; i++) {
        for(int j = 1; j <= N; j++) {
            cout << minTime[i][j] << "   ";
        }
        cout << '\n';
    }
    cout << "\n\n\n";
    */

    long long st = 0, dr = INF, sol = 0;

    while (st <= dr) {
        long long mid = (st + dr) >> 1;

        if (MoreThan(mid)) {
            sol = mid + 1;
            st = mid + 1;
        } else {
            dr = mid - 1;
        }
    }

    cout << sol << '\n';
    return 0;
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 21
• Subtask 3: 0 / 33
• Subtask 4: 0 / 34