Submission #62868

#	Time	Username	Problem	Language	Result	Execution time	Memory
62868		fallingstar	Travelling Merchant (APIO17_merchant)	C++17	12 / 100	134 ms	1704 KiB

merchant

#include <iostream>
#include <algorithm>

#define long long long

using namespace std;

const int N = 100 + 2;
const int K = 1000 + 2;
const long INF = 1e18;

int n, m, k;
int priceBuy[N][K];
int priceSell[N][K];
long dist[N][N];
long num[N][N], den[N][N];

int main()
{
    cin >> n >> m >> k;
    for (int i = 1; i <= n; ++i)
        for (int j = 0; j < k * 2; ++j)
            if (j & 1) cin >> priceSell[i][j / 2];
            else cin >> priceBuy[i][j / 2];

    for (int i = 1; i <= n; ++i)
    {
        fill(dist[i] + 1, dist[i] + 1 + n, INF);
        dist[i][i] = 0;
    }

    for (int i = 0; i < m; ++i)
    {
        int u, v, w; cin >> u >> v >> w;
        dist[u][v] = min(dist[u][v], (long) w);
    }

    // Floyd-Warshall algorithm
    for (int k = 1; k <= n; ++k)
        for (int i = 1; i <= n; ++i)
            for (int j = 1; j <= n; ++j)
                dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);

    for (int i = 1; i <= n; ++i)
        for (int j = 1; j <= n; ++j)
        {
            if (i == j) continue;
            if (dist[i][j] == INF)
            {
                num[i][j] = -1;
                continue;
            }
            for (int l = 0; l < k; ++l)
                if (priceBuy[i][l] != -1 && priceSell[j][l] != -1 && priceBuy[i][l] < priceSell[j][l])
                {
                    num[i][j] = max(num[i][j], (long) priceSell[j][l] - priceBuy[i][l]);
                }
            den[i][j] = dist[i][j];
        }

    for (int l = 1; l <= n; ++l)
        for (int i = 1; i <= n; ++i)
            for (int j = 1; j <= n; ++j)
                if (dist[i][l] != INF && dist[l][j] != INF)
                {
                    double old_val = (den[i][j] != 0 ? (double) num[i][j] / den[i][j] : 0);
                    long new_num = num[i][l] + num[l][j];
                    long new_den = den[i][l] + den[l][j];
                    double new_val = (new_den != 0 ? (double) new_num / new_den : 0);
                    if (new_val > old_val)
                        num[i][j] = new_num, den[i][j] = new_den;
                }

    long ans = 0;
//    for (int i = 1; i <= n; ++i)
//        ans = max(ans, (den[i][i] != 0 ? num[i][i] / den[i][i] : 0));

    for (int l = 0; l < k; ++l)
        for (int j = 2; j <= n; ++j)
            if (priceSell[j][l] > priceBuy[1][l] && priceBuy[1][l] != -1 && dist[1][j] != INF && dist[j][1] != INF)
                ans = max(ans, (priceSell[j][l] - priceBuy[1][l]) / (dist[1][j] + dist[j][1]));

    cout << ans;
    return 0;
}

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