Submission #1159794

#	Time	Username	Problem	Language	Result	Execution time	Memory
1159794		countless	Travelling Merchant (APIO17_merchant)	C++20	100 / 100	60 ms	2120 KiB

merchant

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define endl "\n"
#define sp <<" "<<
#define INF 1e9+21
#define fast_io() ios_base::sync_with_stdio(false); cin.tie(NULL)

void solution() {
    ll n, m, k; cin >> n >> m >> k;

    vector<vector<pair<ll, ll>>> bs(n, vector<pair<ll, ll>>(k)); // haha bs
    for (ll i = 0; i < n; i++) {
        for (ll j = 0; j < k; j++) {
            cin >> bs[i][j].first >> bs[i][j].second;
        }
    }

    ll dist[n][n];
    for (ll i = 0; i < n; i++) {
        for (ll j = 0; j < n; j++) {
            dist[i][j] = INF;
        }
    }

    for (ll i = 0; i < m; i++) {
        ll v, w, t; cin >> v >> w >> t;
        v--; w--;
        dist[v][w] = t;
    }

    // dist between any two nodes
    for (ll l = 0; l < n; l++) {
        for (ll i = 0; i < n; i++) {
            for (ll j = 0; j < n; j++) {
                dist[i][j] = min(dist[i][j], dist[i][l] + dist[l][j]);
            }
        }
    }

    // profit between any two nodes
    ll profit[n][n];
    for (ll i = 0; i < n; i++) {
        for (ll j = 0; j < n; j++) {
            profit[i][j] = 0;
            for (ll l = 0; l < k; l++) {
                if (bs[i][l].first != -1 && bs[j][l].second != -1)
                    profit[i][j] = max(profit[i][j], bs[j][l].second - bs[i][l].first);
            }
        }
    }

    // binary search max efficiency
    ll eff[n][n];
    ll l = 0, r = 1e9+1;
    while (l + 1 < r) {
        ll mid = (l + r) / 2;
        for (ll i = 0; i < n; i++) {
            for (ll j = 0; j < n; j++) {
                eff[i][j] = mid * min(dist[i][j], (ll)INF / mid) - profit[i][j];
            }
        }

        // floyd warshall again
        for (ll kk = 0; kk < n; kk++) {
            for (ll i = 0; i < n; i++) {
                for (ll j = 0; j < n; j++) {
                    eff[i][j] = min(eff[i][j], eff[i][kk] + eff[kk][j]);
                }
            }
        }

        bool flag = false;
        for (ll i = 0; i < n; i++) {
            if (eff[i][i] <= 0) {
                flag = true;
                break;
            }
        }

        if (flag) {
            l = mid;
        } else {
            r = mid;
        }
    }

    cout << l << endl;
    return;
}

signed main() {
    fast_io();

    solution();

    return 0;
}

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