oj.uz

Submission #752246

# Submission time Handle Problem Language Result Execution time Memory
752246 2023-06-02T15:12:11 Z tch1cherin Olympic Bus (JOI20_ho_t4) C++17
37 / 100
 1000 ms 12860 KB 
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define Get(x, i, j) (x[i].empty() ? x.back()[j] : x[i][j])
#include <bits/stdc++.h>
using namespace std;
 
template <typename T>
using min_heap = priority_queue<T, vector<T>, greater<T>>;
 
struct edge {
  int from, to, weight, cost, id;
 
  edge() {}
 
  edge(int _from, int _to, int _weight, int _cost, int _id) : from(_from), to(_to), weight(_weight), cost(_cost), id(_id) {}
};
 
struct node {
  int distance, parent;
 
  node() {
    distance = INT_MAX;
    parent = -1;
  }
 
  node(int _distance, int _parent) : distance(_distance), parent(_parent) {}
};

vector<node> dijkstra(vector<vector<edge>> graph, int start) {
  int n = (int)graph.size();
  vector<node> answer(n);
  min_heap<pair<int, int>> q;
  q.emplace(0, start);
  answer[start].distance = 0;
  while (!q.empty()) {
    auto [d, u] = q.top();
    q.pop();
    if (answer[u].distance > d) {
      continue;
    }
    for (auto [from, to, weight, cost, id] : graph[u]) {
      if (answer[from].distance + weight < answer[to].distance) {
        answer[to] = node(answer[from].distance + weight, id);
        q.emplace(answer[to].distance, to);
      }
    }
  }
  return answer;
}
 
vector<vector<edge>> transpose(vector<vector<edge>> graph) {
  int n = (int)graph.size();
  vector<vector<edge>> new_graph(n);
  for (int u = 0; u < n; u++) {
    for (auto [from, to, weight, cost, id] : graph[u]) {
      new_graph[to].emplace_back(to, from, weight, cost, id);
    }
  }
  return new_graph;
}
 
vector<vector<int>> find_shortest_paths_without_each_edge(vector<vector<edge>> graph, int start) {
  int n = (int)graph.size();
  int m = 0;
  for (int u = 0; u < n; u++) {
    for (auto [from, to, weight, cost, id] : graph[u]) {
      m = max(m, 1 + id);
    }
  }
  vector<node> result = dijkstra(graph, start);
  vector<int> dist(n);
  for (int i = 0; i < n; i++) {
    dist[i] = result[i].distance;
  }
  vector<vector<int>> answer(m);
  for (auto [distance, parent] : result) {
    if (parent != -1) {
      vector<vector<edge>> new_graph = graph;
      bool flag = true;
      for (int u = 0; u < n; u++) {
        for (int i = 0; i < (int)new_graph[u].size(); i++) {
          auto [from, to, weight, cost, id] = new_graph[u][i];
          if (id == parent) {
            new_graph[u].erase(new_graph[u].begin() + i);
            flag = false;
          }  
        }
      }
      vector<node> new_result = dijkstra(new_graph, start);
      answer[parent] = vector<int>(n);
      for (int i = 0; i < n; i++) {
        answer[parent][i] = new_result[i].distance;  
      }
    }
  }
  answer.push_back(dist);
  return answer;
}
 
void solve() {
  int n, m;
  cin >> n >> m;
  vector<vector<edge>> graph(n);
  for (int i = 0; i < m; i++) {
    int from, to, weight, cost;
    cin >> from >> to >> weight >> cost;
    from--, to--;
    graph[from].emplace_back(from, to, weight, cost, i);
  }
  vector<vector<edge>> rev_graph = transpose(graph);
  vector<vector<int>> result_a = find_shortest_paths_without_each_edge(graph, 0);
  vector<vector<int>> result_b = find_shortest_paths_without_each_edge(graph, n - 1);
  vector<vector<int>> rev_result_a = find_shortest_paths_without_each_edge(rev_graph, 0);
  vector<vector<int>> rev_result_b = find_shortest_paths_without_each_edge(rev_graph, n - 1);
  assert(1.0 * clock() / CLOCKS_PER_SEC <= 0.8);
  int ans = INT_MAX;
  if (result_a.back()[n - 1] != INT_MAX && result_b.back()[0] != INT_MAX) {
    ans = result_a.back()[n - 1] + result_b.back()[0];
  }
  for (int u = 0; u < n; u++) {
    for (auto [from, to, weight, cost, id] : graph[u]) {
      int AB = INT_MAX, BA = INT_MAX;
      AB = min(AB, Get(result_a, id, n - 1));
      if (Get(result_a, id, to) != INT_MAX && Get(rev_result_b, id, from) != INT_MAX) {
        AB = min(AB, Get(result_a, id, to) + Get(rev_result_b, id, from) + weight);
      }
      BA = min(BA, Get(result_b, id, 0));
      if (Get(result_b, id, to) != INT_MAX && Get(rev_result_a, id, from) != INT_MAX) {
        BA = min(BA, Get(result_b, id, to) + Get(rev_result_a, id, from) + weight); 
      }
      if (AB == INT_MAX || BA == INT_MAX) {
        continue;
      }
      ans = min(ans, AB + BA + cost);
    }
  }
  cout << (ans == INT_MAX ? -1 : ans) << "\n";
}
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  solve();
}

Compilation message

ho_t4.cpp: In function 'std::vector<std::vector<int> > find_shortest_paths_without_each_edge(std::vector<std::vector<edge> >, int)':
ho_t4.cpp:79:12: warning: variable 'flag' set but not used [-Wunused-but-set-variable]
   79 |       bool flag = true;
      |            ^~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 39 ms 1128 KB Output is correct
2 Correct 3 ms 440 KB Output is correct
3 Correct 47 ms 1184 KB Output is correct
4 Correct 48 ms 1184 KB Output is correct
5 Correct 3 ms 596 KB Output is correct
6 Correct 6 ms 468 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 53 ms 1112 KB Output is correct
11 Correct 53 ms 1180 KB Output is correct
12 Correct 53 ms 1220 KB Output is correct
13 Correct 16 ms 832 KB Output is correct
14 Correct 30 ms 1028 KB Output is correct
15 Correct 31 ms 992 KB Output is correct
16 Correct 30 ms 992 KB Output is correct

Subtask #2
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 680 ms 12628 KB Output is correct
2 Correct 623 ms 12536 KB Output is correct
3 Correct 667 ms 12604 KB Output is correct
4 Correct 46 ms 1416 KB Output is correct
5 Correct 31 ms 1108 KB Output is correct
6 Correct 8 ms 624 KB Output is correct
7 Correct 2 ms 468 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 205 ms 12436 KB Output is correct
10 Correct 202 ms 12596 KB Output is correct
11 Correct 450 ms 12392 KB Output is correct
12 Correct 480 ms 12408 KB Output is correct
13 Correct 426 ms 12328 KB Output is correct
14 Correct 424 ms 12860 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 38 ms 1120 KB Output is correct
2 Correct 8 ms 596 KB Output is correct
3 Correct 271 ms 9952 KB Output is correct
4 Correct 6 ms 468 KB Output is correct
5 Correct 371 ms 12596 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 166 ms 12448 KB Output is correct
9 Correct 158 ms 12496 KB Output is correct
10 Correct 271 ms 12236 KB Output is correct
11 Correct 239 ms 12208 KB Output is correct
12 Correct 237 ms 12484 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 0 ms 212 KB Output is correct
17 Correct 0 ms 212 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 278 ms 12580 KB Output is correct
20 Correct 242 ms 12392 KB Output is correct
21 Correct 244 ms 12508 KB Output is correct
22 Correct 244 ms 12292 KB Output is correct

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 39 ms 1128 KB Output is correct
2 Correct 3 ms 440 KB Output is correct
3 Correct 47 ms 1184 KB Output is correct
4 Correct 48 ms 1184 KB Output is correct
5 Correct 3 ms 596 KB Output is correct
6 Correct 6 ms 468 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 53 ms 1112 KB Output is correct
11 Correct 53 ms 1180 KB Output is correct
12 Correct 53 ms 1220 KB Output is correct
13 Correct 16 ms 832 KB Output is correct
14 Correct 30 ms 1028 KB Output is correct
15 Correct 31 ms 992 KB Output is correct
16 Correct 30 ms 992 KB Output is correct
17 Correct 680 ms 12628 KB Output is correct
18 Correct 623 ms 12536 KB Output is correct
19 Correct 667 ms 12604 KB Output is correct
20 Correct 46 ms 1416 KB Output is correct
21 Correct 31 ms 1108 KB Output is correct
22 Correct 8 ms 624 KB Output is correct
23 Correct 2 ms 468 KB Output is correct
24 Correct 1 ms 212 KB Output is correct
25 Correct 205 ms 12436 KB Output is correct
26 Correct 202 ms 12596 KB Output is correct
27 Correct 450 ms 12392 KB Output is correct
28 Correct 480 ms 12408 KB Output is correct
29 Correct 426 ms 12328 KB Output is correct
30 Correct 424 ms 12860 KB Output is correct
31 Correct 38 ms 1120 KB Output is correct
32 Correct 8 ms 596 KB Output is correct
33 Correct 271 ms 9952 KB Output is correct
34 Correct 6 ms 468 KB Output is correct
35 Correct 371 ms 12596 KB Output is correct
36 Correct 0 ms 212 KB Output is correct
37 Correct 1 ms 212 KB Output is correct
38 Correct 166 ms 12448 KB Output is correct
39 Correct 158 ms 12496 KB Output is correct
40 Correct 271 ms 12236 KB Output is correct
41 Correct 239 ms 12208 KB Output is correct
42 Correct 237 ms 12484 KB Output is correct
43 Correct 0 ms 212 KB Output is correct
44 Correct 0 ms 212 KB Output is correct
45 Correct 0 ms 212 KB Output is correct
46 Correct 0 ms 212 KB Output is correct
47 Correct 0 ms 212 KB Output is correct
48 Correct 0 ms 212 KB Output is correct
49 Correct 278 ms 12580 KB Output is correct
50 Correct 242 ms 12392 KB Output is correct
51 Correct 244 ms 12508 KB Output is correct
52 Correct 244 ms 12292 KB Output is correct
53 Correct 753 ms 12500 KB Output is correct
54 Correct 735 ms 12480 KB Output is correct
55 Correct 687 ms 12640 KB Output is correct
56 Correct 46 ms 1184 KB Output is correct
57 Correct 46 ms 1232 KB Output is correct
58 Correct 548 ms 10152 KB Output is correct
59 Correct 593 ms 10124 KB Output is correct
60 Correct 632 ms 10068 KB Output is correct
61 Correct 540 ms 10036 KB Output is correct
62 Correct 543 ms 10196 KB Output is correct
63 Correct 569 ms 10188 KB Output is correct
64 Execution timed out 1048 ms 6232 KB Time limit exceeded
65 Halted 0 ms 0 KB -