Submission #704138

#	Time	Username	Problem	Language	Result	Execution time	Memory
704138		four_specks	Travelling Merchant (APIO17_merchant)	C++17	0 / 100	40 ms	1996 KiB

merchant

#include <bits/stdc++.h>

using namespace std;

namespace
{
} // namespace

void solve()
{
    int n, m, k;
    cin >> n >> m >> k;

    vector a(n, vector<array<long, 2>>(k));
    for (int u = 0; u < n; u++)
    {
        for (auto &[x, y] : a[u])
            cin >> x >> y;
    }

    vector<tuple<int, int, long>> edges(m);
    for (auto &[u, v, w] : edges)
        cin >> u >> v >> w, --u, --v;

    vector dist(n, vector<long>(n, INT_MAX));
    for (auto [u, v, w] : edges)
        dist[u][v] = min(dist[u][v], w);
    for (int s = 0; s < n; s++)
    {
        for (int u = 0; u < n; u++)
        {
            for (int v = 0; v < n; v++)
                dist[u][v] = min(dist[u][v], dist[u][s] + dist[s][v]);
        }
    }

    auto frac = [&](const array<long, 2> &lhs, const array<long, 2> &rhs) -> array<long, 2>
    { return {lhs[0] + rhs[0], lhs[1] + rhs[1]}; };

    auto comp = [&](const array<long, 2> &lhs, const array<long, 2> &rhs) -> bool
    { return lhs[0] * rhs[1] < rhs[0] * lhs[1]; };

    vector dp(n, vector<array<long, 2>>(n, {0, INT_MAX}));
    for (int u = 0; u < n; u++)
    {
        for (int v = 0; v < n; v++)
        {
            long x = 0;
            for (int i = 0; i < k; i++)
            {
                if (min(a[u][i][0], a[v][i][1]) != -1 && a[v][i][1] > a[u][i][0])
                    x = max(x, a[v][i][1] - a[u][i][0]);
            }
            dp[u][v] = {x, dist[u][v]};
        }
    }
    for (int s = 0; s < n; s++)
    {
        for (int u = 0; u < n; u++)
        {
            for (int v = 0; v < n; v++)
            {
                if (max(dp[u][s][1], dp[s][v][1]) != INT_MAX)
                    dp[u][v] = max(dp[u][v], frac(dp[u][s], dp[s][v]), comp);
            }
        }
    }

    long res = 0;
    for (int u = 0; u < n; u++)
        res = max(res, dp[u][u][0] / dp[u][u][1]);

    cout << res << '\n';
}

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

    solve();

    return 0;
}

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