oj.uz

Submission #827571

# Submission time Handle Problem Language Result Execution time Memory
827571 2023-08-16T14:50:12 Z taher Olympic Bus (JOI20_ho_t4) C++17
16 / 100
 33 ms 4168 KB 
#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "C:\GCC\debug.h"
#else
#define debug(...) void(42)
#endif

const long long inf = 123165465792545;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  int n, m;
  cin >> n >> m;
  vector<vector<array<int, 4>>> adj(n);
  vector<vector<array<int, 4>>> inv(n);
  vector<array<int, 4>> edges;
  for (int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    int c, d;
    cin >> c >> d;
    --u, --v;
    adj[u].push_back({v, c, d, i});
    inv[v].push_back({u, c, d, i});
    edges.push_back({u, v, c, d});
  }

  array<int, 2> perm;
  perm[0] = 0;
  perm[1] = n - 1;
  vector<vector<long long>> d2(n, vector<long long> (n, inf));

  auto Floyd = [&]() {
    for (int i = 0; i < n; i++) {
      d2[i][i] = 0;
    }
    for (int i = 0; i < n; i++) {
      for (auto v : adj[i]) {
        d2[i][v[0]] = min(d2[i][v[0]], 1LL * v[1]);
      }
    }
    for (int k = 0; k < n; k++) {
      for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
          d2[i][j] = min(d2[i][j], d2[i][k] + d2[k][j]);
        }
      }
    }
  };

  Floyd();
  auto Update = [&](int forbidden, int source, int to, int cost) {
    vector<long long> dist(n, inf);
    dist[perm[1]] = 0;
    priority_queue<array<long long, 2>, vector<array<long long, 2>>, greater<array<long long, 2>>> que;
    que.push({0, perm[1]});

    while (!que.empty()) {
      auto cur = que.top();
      que.pop();

      if (dist[cur[1]] != cur[0]) {
        continue;
      }

      if (cur[1] == source) {
        if (dist[to] > 1LL * cur[0] + cost) {
          dist[to] = 1LL * cur[0] + cost;
          que.push({dist[to], to});
        }
      }

      for (auto v : adj[cur[1]]) {
        if (v[3] == forbidden) {
          continue;      
        } else {
          if (dist[v[0]] > cur[0] + v[1]) {
            dist[v[0]] = cur[0] + v[1];
            que.push({dist[v[0]], v[0]});
          }
        }
      }
    }
    return dist[perm[0]];
  };

  vector<int> cntA(n);
  vector<int> cntB(n);
  vector<int> middleA(n, -1);
  vector<int> middleB(n, -1);
  for (int i = 0; i < n; i++) {
    for (auto v : inv[i]) {
      if (d2[perm[0]][v[0]] + v[1] == d2[perm[0]][i]) {
        cntA[i]++;
        middleA[i] = v[0];
      }
    }
  }
  for (int i = 0; i < n; i++) {
    for (auto v : adj[i]) {
      if (d2[v[0]][perm[1]] + v[1] == d2[i][perm[1]]) {
        cntB[i]++;
        middleB[i] = v[0];
      }
    }
  }


  vector<int> cntC(n);
  vector<int> cntD(n);
  vector<int> middleC(n, -1);
  vector<int> middleD(n, -1);
  for (int i = 0; i < n; i++) {
    for (auto v : inv[i]) {
      if (d2[perm[1]][v[0]] + v[1] == d2[perm[1]][i]) {
        cntC[i]++;
        middleC[i] = v[0];
      }
    }
  }
  for (int i = 0; i < n; i++) {
    for (auto v : adj[i]) {
      if (d2[v[0]][perm[0]] + v[1] == d2[i][perm[0]]) {
        cntD[i]++;
        middleD[i] = v[0];
      }
    }
  }

  long long res = inf;
  res = min(res, d2[perm[0]][perm[1]] + d2[perm[1]][perm[0]]);
  for (int i = 0; i < m; i++) {
    int u = edges[i][0];
    int v = edges[i][1];
    int c = edges[i][2];
    int d = edges[i][3];

    long long path_from_beg = 0;

    bool canA = true;
    bool canB = true;

    canA &= (cntA[v] > 1 || middleA[v] != u);
    canB &= (cntB[u] > 1 || middleB[u] != v);

    if (canA && canB) {
      path_from_beg = min(d2[perm[0]][perm[1]], d2[perm[0]][v] + d2[u][perm[1]] + c);
    } else {
      swap(perm[0], perm[1]);
      path_from_beg = Update(i, v, u, c);
      swap(perm[0], perm[1]);
    }

    canA = true;
    canB = true;

    canA &= (cntC[v] > 1 || middleC[v] != u);
    canB &= (cntD[u] > 1 || middleD[u] != v);

    long long path_from_end = 0;
    if (canA && canB) {
      path_from_end = min(d2[perm[1]][perm[0]], d2[perm[1]][v] + d2[u][perm[0]] + c);
    } else {
      path_from_end = Update(i, v, u, c);
    }

    long long tot = path_from_beg + path_from_end + d;
    res = min(res, tot);
  }

  if (res == inf) {
    cout << -1 << '\n';
  } else {
    cout << res << '\n';
  }
  return 0;
}

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 724 KB Output is correct
2 Correct 7 ms 596 KB Output is correct
3 Correct 29 ms 748 KB Output is correct
4 Correct 31 ms 748 KB Output is correct
5 Correct 3 ms 328 KB Output is correct
6 Correct 11 ms 676 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 2 ms 340 KB Output is correct
10 Correct 28 ms 756 KB Output is correct
11 Correct 20 ms 760 KB Output is correct
12 Correct 20 ms 764 KB Output is correct
13 Correct 10 ms 760 KB Output is correct
14 Correct 19 ms 756 KB Output is correct
15 Correct 14 ms 752 KB Output is correct
16 Correct 16 ms 752 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 3908 KB Output is correct
2 Correct 31 ms 3832 KB Output is correct
3 Correct 33 ms 3880 KB Output is correct
4 Correct 8 ms 828 KB Output is correct
5 Correct 7 ms 724 KB Output is correct
6 Correct 8 ms 716 KB Output is correct
7 Correct 7 ms 596 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 24 ms 4040 KB Output is correct
10 Correct 27 ms 3988 KB Output is correct
11 Correct 22 ms 3908 KB Output is correct
12 Correct 23 ms 3900 KB Output is correct
13 Correct 23 ms 3808 KB Output is correct
14 Correct 23 ms 4168 KB Output is correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 724 KB Output is correct
2 Correct 12 ms 680 KB Output is correct
3 Correct 18 ms 3316 KB Output is correct
4 Correct 7 ms 684 KB Output is correct
5 Correct 21 ms 3824 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 29 ms 3988 KB Output is correct
9 Correct 24 ms 3892 KB Output is correct
10 Incorrect 21 ms 3864 KB Output isn't correct
11 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 724 KB Output is correct
2 Correct 7 ms 596 KB Output is correct
3 Correct 29 ms 748 KB Output is correct
4 Correct 31 ms 748 KB Output is correct
5 Correct 3 ms 328 KB Output is correct
6 Correct 11 ms 676 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 2 ms 340 KB Output is correct
10 Correct 28 ms 756 KB Output is correct
11 Correct 20 ms 760 KB Output is correct
12 Correct 20 ms 764 KB Output is correct
13 Correct 10 ms 760 KB Output is correct
14 Correct 19 ms 756 KB Output is correct
15 Correct 14 ms 752 KB Output is correct
16 Correct 16 ms 752 KB Output is correct
17 Correct 22 ms 3908 KB Output is correct
18 Correct 31 ms 3832 KB Output is correct
19 Correct 33 ms 3880 KB Output is correct
20 Correct 8 ms 828 KB Output is correct
21 Correct 7 ms 724 KB Output is correct
22 Correct 8 ms 716 KB Output is correct
23 Correct 7 ms 596 KB Output is correct
24 Correct 0 ms 212 KB Output is correct
25 Correct 24 ms 4040 KB Output is correct
26 Correct 27 ms 3988 KB Output is correct
27 Correct 22 ms 3908 KB Output is correct
28 Correct 23 ms 3900 KB Output is correct
29 Correct 23 ms 3808 KB Output is correct
30 Correct 23 ms 4168 KB Output is correct
31 Correct 10 ms 724 KB Output is correct
32 Correct 12 ms 680 KB Output is correct
33 Correct 18 ms 3316 KB Output is correct
34 Correct 7 ms 684 KB Output is correct
35 Correct 21 ms 3824 KB Output is correct
36 Correct 0 ms 212 KB Output is correct
37 Correct 0 ms 212 KB Output is correct
38 Correct 29 ms 3988 KB Output is correct
39 Correct 24 ms 3892 KB Output is correct
40 Incorrect 21 ms 3864 KB Output isn't correct
41 Halted 0 ms 0 KB -