Submission #699390

#	Time	Username	Problem	Language	Result	Execution time	Memory
699390		CatalinT	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	91 ms	3376 KiB

merchant

#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>

using namespace std;

using int64 = long long;

const double EPS = 1e-9;
const int64 INF = (1LL<<60);

struct Market {
    int b;
    int s;
};

int N, M, K;
vector<vector<Market>> market;
vector<vector<int64>> dist;

vector<vector<int>> profit;

bool go(int64 r) {
    vector<vector<int64>> d(N, vector<int64>(N, INF));

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            if (i != j && dist[i][j] < INF) {
                d[i][j] = min(d[i][j], -profit[i][j] + r * dist[i][j]);
            }
        }
    }
   
    for (int k = 0; k < N; k++)
        for (int i = 0; i < N; i++)
            for (int j = 0; j < N; j++)
                d[i][j] = min(d[i][j], d[i][k] + d[k][j]);

    for (int i = 0; i < N; i++) {
        if (d[i][i] <= 0)
            return true;
    }

    return false;
}

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

    cin >> N >> M >> K;
    market = vector<vector<Market>>(N, vector<Market>(K));

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < K; j++) {
            cin >> market[i][j].b >> market[i][j].s;
        }
    }

    dist = vector<vector<int64>>(N, vector<int64>(N, INF));
    for (int i = 0; i < N; i++)
        dist[i][i] = 0;

    for (int i = 0; i < M; i++) {
        int x, y, w;
        cin >> x >> y >> w;
        x--, y--;
        dist[x][y] = min(dist[x][y], (int64)w);
    }

    for (int k = 0; k < N; k++) {
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
            }
        }
    }

    profit = vector<vector<int>>(N, vector<int>(N));

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            if (dist[i][j] < INF) {
                for (int k = 0; k < K; k++) {
                    if (market[i][k].b != -1 && market[j][k].s != -1) {
                        profit[i][j] = max(profit[i][j], market[j][k].s - market[i][k].b);
                    }
                }
            }
        }
    }

    int64 l = 1, r = (1LL<<30), sol = 0;

    while (l <= r) {
        int64 m = (l + r) >> 1;
        if (go(m)) {
            sol = m;
            l = m + 1;
        } else {
            r = m - 1;
        }
    }

    cout << sol << "\n";

    return 0;
}

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