Submission #1185135

#	Time	Username	Problem	Language	Result	Execution time	Memory
1185135		eradax	Cities (BOI16_cities)	C++20	100 / 100	606 ms	31512 KiB

cities

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;

#define check(a, b) ((a >> b) & 1)
#define sz(c) ((int)c.size())

#ifdef DBG
  #define dbg(expr)                                                          \
    cerr << "[" << __FUNCTION__ << ", " << __LINE__ << "] " << #expr << ": " \
         << expr << endl;
#else
  #define dbg(...)
#endif

using ll = long long;
#define int ll

template <typename T, typename U>
ostream& operator<<(ostream& o, pair<T, U> v) {
  o << "{ ";
  o << v.first << ", " << v.second;
  o << "}";
  return o;
}

template <typename T>
ostream& operator<<(ostream& o, vector<T> v) {
  o << "{ ";
  for (auto& i : v)
    o << i << ", ";
  o << "}";
  return o;
}

template <typename T>
ostream& operator<<(ostream& o, vector<vector<T>> v) {
  o << "{ ";
  for (auto& i : v)
    o << i << ", ";
  o << "}";
  return o;
}

const int INF = 3e18;

using vi = vector<int>;
using vvi = vector<vi>;

using pi = pair<int, int>;

signed main() {
  int n, k, m;
  cin >> n >> k >> m;


  priority_queue<pi, vector<pi>, greater<pi>> pq;

  dbg(n);
  dbg(k);
  dbg(m);

  vi imp(k);
  for (auto& i : imp) {
    cin >> i, i--;
  }

  k--;

  dbg(imp);

  vector<vector<pair<int, int>>> adj(n);
  for (int i = 0; i < m; i++) {
    int a, b, c;
    cin >> a >> b >> c;
    a--, b--;
    adj[a].emplace_back(b, c);
    adj[b].emplace_back(a, c);
  }

  dbg(adj);

  vvi dp(1 << k, vi(n, INF));
  for (int i = 0; i < k; i++) {
    dp[1 << i][imp[i]] = 0;
  }

  for (int mask = 1; mask < 1 << k; mask++) {
    for (int nmask = mask; nmask > 0; nmask=(nmask-1)&mask) {
      int omask = nmask ^ mask;
      if (omask < nmask) continue;
      for (int i = 0; i < n; i++) {
        dp[mask][i] = min(dp[mask][i], dp[nmask][i] + dp[omask][i]);
      }
    }

    dbg(dp[mask]);

    dbg(mask);

    for (int i = 0; i < n; i++) {
      if (dp[mask][i] == INF)
        continue;
      pq.emplace(dp[mask][i], i);
    }

    vi vis(n);

    while (!pq.empty()) {
      auto [w, u] = pq.top();
      pq.pop();
      // w = -w;
      
      if (vis[u]) continue;
      vis[u] = 1;

      for (auto [v, vw] : adj[u]) {
        if (dp[mask][v] <= w + vw)
          continue;
        dp[mask][v] = w + vw;
        pq.emplace(dp[mask][v], v);
      }
    }

    dbg(dp[mask]);
  }

  cout << dp[(1<<k)-1][imp[k]] << endl;
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26