Submission #1117207

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117207		ThegeekKnight16	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	80 ms	4344 KiB

merchant

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 1e9 + 10;

bool bellman(int x, const vector<vector<int>> &preco, const vector<vector<int>> &tempo, const int &N)
{
    vector<vector<int>> p(N+1, vector<int>(N+1));
    for (int i = 1; i <= N; i++)
        for (int j = 1; j <= N; j++)
            p[i][j] = x * tempo[i][j] - preco[i][j];
    for (int i = 1; i <= N; i++) p[i][i] = INF;

    vector<int> dist(N+1, 0);
    for (int t = 1; t <= N+1; t++)
        for (int i = 1; i <= N; i++)
            for (int j = 1; j <= N; j++)
                dist[j] = min(dist[j], dist[i] + p[i][j]);

    for (int i = 1; i <= N; i++)
        for (int j = 1; j <= N; j++)
            if (dist[j] > dist[i] + p[i][j]) return true;

    vector<vector<int>> grafo(N+1);
    vector<int> grau(N+1);
    for (int i = 1; i <= N; i++)
        for (int j = 1; j <= N; j++)
            if (dist[j] == dist[i] + p[i][j])
                grafo[i].push_back(j), grau[j]++;
    queue<int> q;
    for (int i = 1; i <= N; i++) if (grau[i] == 0) q.push(i);
    while (!q.empty())
    {
        int cur = q.front(); q.pop();
        for (auto viz : grafo[cur])
            if (--grau[viz] == 0)
                q.push(viz);
    }
    
    return *max_element(grau.begin(), grau.end());
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int N, M, K;
    cin >> N >> M >> K;
    vector<vector<pair<int, int>>> items(N+1, vector<pair<int, int>>(K));
    for (int i = 1; i <= N; i++)
        for (auto &[B, S] : items[i]) cin >> B >> S;

    vector<vector<int>> preco(N+1, vector<int>(N+1, 0));
    for (int i = 1; i <= N; i++)
        for (int j = 1; j <= N; j++)
            for (int k = 0; k < K; k++)
            {
                auto [Bi, Si] = items[i][k];
                auto [Bj, Sj] = items[j][k];
                if (Bi == -1 || Sj == -1) continue;
                if (Bi >= Sj) continue;
                preco[i][j] = max(preco[i][j], Sj - Bi);
            }

    vector<vector<int>> tempo(N+1, vector<int>(N+1, INF));
    for (int i = 1; i <= M; i++)
    {
        int X, Y, P;
        cin >> X >> Y >> P;
        tempo[X][Y] = min(tempo[X][Y], P);
    }
    for (int i = 1; i <= N; i++) tempo[i][i] = 0;
    for (int k = 1; k <= N; k++)
        for (int i = 1; i <= N; i++)
            for (int j = 1; j <= N; j++)
                tempo[i][j] = min(tempo[i][j], tempo[i][k] + tempo[k][j]);

    int ini = 0, fim = INF;
    while (ini < fim)
    {
        int m = (ini + fim + 1) >> 1;
        if (bellman(m, preco, tempo, N)) ini = m;
        else fim = m-1;
    }
    cout << fim << '\n';
}

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