Submission #842631

#	Time	Username	Problem	Language	Result	Execution time	Memory
842631		tch1cherin	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	88 ms	2652 KiB

merchant

#include <bits/stdc++.h>
using namespace std;

const long long INF = 1LL << 60;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int N, M, K;
  cin >> N >> M >> K;
  vector<vector<int>> B(N, vector<int>(K)), S(N, vector<int>(K));
  for (int i = 0; i < N; i++) {
    for (int j = 0; j < K; j++) {
      cin >> B[i][j] >> S[i][j];
    }
  }
  vector<vector<pair<int, int>>> G(N);
  for (int i = 0; i < M; i++) {
    int u, v, w;
    cin >> u >> v >> w;
    u--, v--;
    G[u].push_back({v, w});
  }
  vector<vector<int>> profit(N, vector<int>(N));
  for (int i = 0; i < N; i++)
    for (int j = 0; j < N; j++)
      if (i != j)
        for (int k = 0; k < K; k++)
          if (S[j][k] != -1 && B[i][k] != -1)
            profit[i][j] = max(profit[i][j], S[j][k] - B[i][k]);

  vector<vector<long long>> dist(N, vector<long long>(N, INF));
  for (int u = 0; u < N; u++) {
    dist[u][u] = 0;
    for (auto [v, t] : G[u]) {
      dist[u][v] = t;
    }
  }
  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]);

  int l = 0, r = 1 << 30;
  while (r > l + 1) {
    int mid = (l + r) / 2;
    vector<vector<long long>> cost(N, vector<long long>(N));
    for (int i = 0; i < N; i++) {
      for (int j = 0; j < N; j++) {
        if (dist[i][j] == INF || i == j) {
          cost[i][j] = INF;
        } else {
          cost[i][j] = 1LL * dist[i][j] * mid - profit[i][j];
        }
      }
    }
    for (int k = 0; k < N; k++)
      for (int i = 0; i < N; i++)
        for (int j = 0; j < N; j++) {
          cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);
          cost[i][j] = max(cost[i][j], -INF);
          cost[i][j] = min(cost[i][j], INF);
        }

    bool good = false;
    for (int i = 0; i < N; i++) {
      if (cost[i][i] <= 0) {
        good = true;
      }
    }
    if (good) {
      l = mid;
    } else {
      r = mid;
    }
  }
  cout << l << "\n";
}

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