Submission #555791

#	Time	Username	Problem	Language	Result	Execution time	Memory
555791		cadmiumsky	Travelling Merchant (APIO17_merchant)	C++14	21 / 100	117 ms	724 KiB

merchant

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
#define int ll
const ll inf = 1e9L + 5;
const int nmax = 105;

void fw(int n, ll dist[nmax][nmax]) {
  for(int h = 0; h < n; h++) {
    for(int i = 0; i < n; i++) {
      for(int j = 0; j < n; j++)
        dist[i][j] = max(-inf, min(dist[i][j], dist[i][h] + dist[h][j]));
    }
  }
}

ll dist[nmax][nmax], cost[nmax][nmax], alter[nmax][nmax];
ll buy[nmax][nmax], sell[nmax][nmax];

bool check(int n, int coef) {
  //cerr << "Alter with coef " << coef << '\n';
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < n; j++)
      alter[i][j] = -(cost[i][j] - dist[i][j] * coef);
  }
  fw(n, alter);
  for(int i = 0; i < n; i++) {
    if(alter[i][i] <= 0)
      return 1;
  }
  return 0;
}

signed main() {
  int n, m, k;
  cin >> n >> m >> k;
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < k; j++) {
      cin >> buy[i][j] >> sell[i][j];
      if(buy[i][j] == -1)
        buy[i][j] = inf;
      if(sell[i][j] == -1)
        sell[i][j] = -inf;
    }
  }
  for(int i = 0; i< n; i++)
    for(int j = 0; j < n; j++)
      dist[i][j] = inf;
  for(int i = 0, x, y, c; i < m; i++)
    cin >> x >> y >> c, --x, --y, dist[x][y] = min(dist[x][y], c);
  fw(n, dist);
  for(int i = 0; i < n; i++) {
    for(int j = 0; j < n; j++) {
      cost[i][j] = 0;
      for(int h = 0; h < k; h++)
        cost[i][j] = max(cost[i][j], sell[j][h] - buy[i][h]);
    }
  }
  int l = 0, r = inf, mid;
  while(r - l > 1) {
    mid = l + r >> 1;
    if(check(n, mid))
      l = mid;
    else 
      r = mid;
  }
  cout << l << '\n';
}

Compilation message (stderr)

merchant.cpp: In function 'int main()':
merchant.cpp:62:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   62 |     mid = l + r >> 1;
      |           ~~^~~

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