Submission #601328

#	Time	Username	Problem	Language	Result	Execution time	Memory
601328		narvalo	Ferries (NOI13_ferries)	C++17	0 / 40	110 ms	15328 KiB

ferries

#include <bits/stdc++.h>

using namespace std;

int ferries(int n , int m , vector<int> a , vector<int> b , vector<int> c) {
  vector<vector<pair<int , int>>> adj(n);
  for (int i = 0 ; i < m ; i++) {
    a[i] -= 1 , b[i] -= 1;
    adj[a[i]].emplace_back(b[i] , c[i]);
  }
  vector<int> mx(n);
  for (int i = 0 ; i < n ; i++) {
    for (auto x : adj[i]) {
      mx[i] = max(mx[i] , x.second);
    }
  }
  const int INF = (int)1e9;
  vector<int> dest(n , INF);
  #define pi pair<int , int>
  priority_queue<pi , vector<pi> , greater<pi>> pq;
  dest[0] = 0;
  pq.emplace(dest[0] , 0);
  while (!pq.empty()) {
    auto X = pq.top();
    pq.pop();
    if (X.first != dest[X.second]) continue;
    for (auto x :  adj[X.second]) {
      if (dest[x.first] > X.first + mx[X.second]) {
        dest[x.first] = X.first + mx[X.second];
        pq.emplace(dest[x.first] , x.first);
      }
    }
  }
  int res = dest[n - 1];
  return res;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n , m;
  cin >> n >> m;
  vector<int> a(m) , b(m) , c(m);
  for (int i = 0 ; i < m ; i += 1) {
    cin >> a[i] >> b[i] >> c[i];
  }
  cout << ferries(n , m , a , b , c) << '\n';
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 10
• Subtask 3: 0 / 11
• Subtask 4: 0 / 12