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Submission #601367

# Submission time Handle Problem Language Result Execution time Memory
601367 2022-07-21T18:54:27 Z narvalo Ferries (NOI13_ferries) C++17
28 / 40
 160 ms 30172 KB 
#include <bits/stdc++.h>
 
using namespace std;
 
#define int long long
 
const int INF = (int)1e12;
 
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> dp(n , -1) , vis(n);
  function<long long(int)> Solve = [&](int node) -> long long {
    if (node == n - 1) {
      return 0;
    }
    if (vis[node] == 1) {
      return INF;
    }
    if (dp[node] != -1) {
      return dp[node];
    }
    vis[node] = 1;
    vector<int> d , s;
    for (auto x : adj[node]) {
      int g = Solve(x.first);
      d.emplace_back(g);
      s.emplace_back(x.second);
    }
    sort(d.begin() , d.end());
    sort(s.begin() , s.end());
    auto Get = [&]() {
      int val = INF;
      for (int i = 0 ; i < (int)s.size() ; i += 1) {
        val = min(val , s[i] + d[(int)s.size() - i - 1]);
      }
      return val;
    };
    int res = Get();
    reverse(s.begin() , s.end());
    reverse(d.begin() , d.end());
    res = max(res , Get());
    vis[node] = 2;
    return dp[node] = res;
  };
  int res = Solve(0);
  return res;
}
 
int32_t 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
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 8 ms 2384 KB Output is correct
4 Correct 77 ms 21160 KB Output is correct
5 Correct 78 ms 21176 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 8 ms 2308 KB Output is correct
4 Correct 37 ms 10552 KB Output is correct
5 Correct 49 ms 13280 KB Output is correct

Subtask #3
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 3156 KB Output is correct
2 Correct 11 ms 3156 KB Output is correct
3 Correct 141 ms 28344 KB Output is correct
4 Correct 137 ms 26056 KB Output is correct
5 Correct 133 ms 26092 KB Output is correct

Subtask #4
0 / 12.0

# Verdict Execution time Memory Grader output
1 Incorrect 160 ms 30172 KB Output isn't correct
2 Halted 0 ms 0 KB -