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Submission #1049876

# Submission time Handle Problem Language Result Execution time Memory
1049876 2024-08-09T05:52:14 Z avighna Relay Marathon (NOI20_relaymarathon) C++17
25 / 100
 840 ms 211532 KB 
#include <bits/stdc++.h>

typedef long long ll;

const ll inf = 1e15;

struct Edge {
  ll u, v, w;
};

int main() {
  std::ios_base::sync_with_stdio(false);
  std::cin.tie(nullptr);

  ll n, m, k;
  std::cin >> n >> m >> k;
  std::vector<std::vector<std::pair<ll, ll>>> adj(n + 1);
  std::vector<Edge> edges;
  for (ll i = 0, u, v, w; i < m; ++i) {
    std::cin >> u >> v >> w;
    adj[u].push_back({v, w});
    adj[v].push_back({u, w});
    edges.push_back({u, v, w});
  }
  std::vector<ll> A(k);
  std::vector<bool> special(n + 1);
  for (auto &i : A) {
    std::cin >> i;
    special[i] = true;
  }

  auto get_best = [&]() {
    std::priority_queue<std::pair<ll, std::pair<ll, ll>>> pq;
    std::vector<ll> d(n + 1, inf);
    for (auto &i : A) {
      pq.push({0, {i, i}});
      d[i] = 0;
    }
    std::vector<std::pair<ll, ll>> closest_special(n + 1);
    std::vector<bool> vis(n + 1);
    while (!pq.empty()) {
      ll node = pq.top().second.first, source = pq.top().second.second,
         dist = -pq.top().first;
      pq.pop();
      if (vis[node]) {
        continue;
      }
      vis[node] = true;
      closest_special[node] = {source, dist};
      for (auto &[i, i_d] : adj[node]) {
        if (dist + i_d < d[i]) {
          d[i] = dist + i_d;
          pq.push({-d[i], {i, source}});
        }
      }
    }

    std::pair<ll, std::pair<ll, ll>> ans = {inf, {0, 0}};
    for (auto &[u, v, w] : edges) {
      if (special[u] and special[v]) {
        ans = std::min(ans, {w, {u, v}});
      }
    }
    for (auto &[u, v, w] : edges) {
      if (closest_special[u].first != closest_special[v].first) {
        ans = std::min(
            ans, {closest_special[u].second + w + closest_special[v].second,
                  {closest_special[u].first, closest_special[v].first}});
      }
    }
    return ans;
  };

  auto sssp = [&](ll x) {
    std::priority_queue<std::pair<ll, ll>> pq;
    pq.push({0, x});
    std::vector<ll> ans(n + 1, inf);
    std::vector<bool> vis(n + 1);
    ans[x] = 0;
    while (!pq.empty()) {
      ll node = pq.top().second, d = -pq.top().first;
      pq.pop();
      if (vis[node]) {
        continue;
      }
      vis[node] = true;
      for (auto &[i, dist] : adj[node]) {
        if (d + dist < ans[i]) {
          ans[i] = d + dist;
          pq.push({-ans[i], i});
        }
      }
    }
    return ans;
  };

  auto best = get_best();
  auto &[u, v] = best.second;
  special[u] = special[v] = false;
  A.erase(std::remove(A.begin(), A.end(), u), A.end());
  A.erase(std::remove(A.begin(), A.end(), v), A.end());
  auto second_best = get_best();
  ll ans = best.first + second_best.first;
  auto sssp1 = sssp(u);
  std::vector<std::pair<ll, ll>> best1;
  for (ll x = 1; x <= n; ++x) {
    if (x != v and special[x]) {
      best1.push_back({sssp1[x], x});
    }
  }
  auto sssp2 = sssp(v);
  std::vector<std::pair<ll, ll>> best2;
  for (ll y = 1; y <= n; ++y) {
    if (y != u and special[y]) {
      best2.push_back({sssp1[y], y});
    }
  }
  std::sort(best1.begin(), best1.end());
  std::sort(best2.begin(), best2.end());
  for (ll i = 0; i < std::min(best1.size(), size_t(5)); ++i) {
    for (ll j = 0; j < std::min(best2.size(), size_t(5)); ++j) {
      if (best1[i].second != best2[j].second) {
        ans = std::min(ans, best1[i].first + best2[j].first);
      }
    }
  }
  std::cout << ans << '\n';
}

Compilation message

RelayMarathon.cpp: In function 'int main()':
RelayMarathon.cpp:120:20: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'const long unsigned int' [-Wsign-compare]
  120 |   for (ll i = 0; i < std::min(best1.size(), size_t(5)); ++i) {
      |                  ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
RelayMarathon.cpp:121:22: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'const long unsigned int' [-Wsign-compare]
  121 |     for (ll j = 0; j < std::min(best2.size(), size_t(5)); ++j) {
      |                    ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 12.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 10756 KB Output is correct
2 Correct 4 ms 5976 KB Output is correct
3 Correct 813 ms 210664 KB Output is correct
4 Correct 412 ms 88316 KB Output is correct
5 Correct 104 ms 21108 KB Output is correct
6 Correct 85 ms 17032 KB Output is correct
7 Correct 114 ms 23556 KB Output is correct
8 Correct 52 ms 11016 KB Output is correct
9 Correct 68 ms 15616 KB Output is correct
10 Correct 48 ms 12608 KB Output is correct
11 Correct 809 ms 211280 KB Output is correct
12 Correct 50 ms 13320 KB Output is correct
13 Correct 235 ms 55292 KB Output is correct
14 Correct 107 ms 22808 KB Output is correct
15 Correct 779 ms 209432 KB Output is correct
16 Correct 25 ms 9996 KB Output is correct
17 Correct 574 ms 138664 KB Output is correct
18 Correct 6 ms 5784 KB Output is correct
19 Correct 840 ms 211532 KB Output is correct
20 Correct 100 ms 23040 KB Output is correct
21 Correct 81 ms 20220 KB Output is correct
22 Correct 42 ms 12036 KB Output is correct
23 Correct 18 ms 8464 KB Output is correct
24 Correct 561 ms 149192 KB Output is correct
25 Correct 78 ms 15888 KB Output is correct
26 Correct 36 ms 11532 KB Output is correct
27 Correct 54 ms 14080 KB Output is correct
28 Correct 9 ms 7140 KB Output is correct
29 Correct 96 ms 22868 KB Output is correct
30 Correct 193 ms 43480 KB Output is correct

Subtask #4
0 / 58.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Output isn't correct
2 Halted 0 ms 0 KB -