Submission #887270

#	Time	Username	Problem	Language	Result	Execution time	Memory
887270		vjudge1	Cities (BOI16_cities)	C++17	22 / 100	2258 ms	47472 KiB

cities

/// Seeing the beauty through the...
/// Pain!
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define fast_io ios::sync_with_stdio(false);cin.tie(NULL);
#define file_io freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
#define FOR(i,k,n) for(int i = k; i < n; ++ i)
#define debf cout<<"(0-0)\n";
#define all(x) x.begin(), x.end()
#define dec(x) cout << fixed << setprecision(x);
#define pf push_front
#define ppf pop_front
#define dash " ------- "
#define what(x) cerr << #x << " is " << x << endl;
#define eb emplace_back
//#define int short int
#define int long long
#define sz(s) (int) (s.size())
#define fl cout.flush()

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <int, pii> pip;
typedef pair <pii, int> ppi;
typedef pair <ll, ll> pll;
typedef unsigned long long ull;
typedef long double ld;

template <class T> using max_heap = priority_queue <T, vector <T>, less <T> >;
template <class T> using min_heap = priority_queue <T, vector <T>, greater <T> >;
//template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

constexpr int MOD = 1e9 + 7, N = 2e5 + 8, M = 1e5 + 4, SQ = 300, INF = 1e15 + 8, LGN = 22, mod = 998244353, P = 131113;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

bool mark[N];
int n, k, m, dist[N][(1 << 5) + 1], ans = INF;
vector <pii> adj[N];
priority_queue <pii> pq;

void dijk (int mask){
  for (int i = 0; i < n; ++ i){
    mark[i] = false;
    if (dist[i][mask] < INF){
      pq.push({dist[i][mask], i});
    }
  }
  while (pq.size()){
    pii p = pq.top();
    pq.pop();
    int x = p.S;
    if (mark[x]){
      continue;
    }
    mark[x] = true;
    for (pii i : adj[x]){
      if (dist[i.S][mask] > dist[x][mask] + i.F){
        dist[i.S][mask] = dist[x][mask] + i.F;
        pq.push({dist[i.S][mask], i.S});
      }
    }
  }
  return;
}

int32_t main(){
  fast_io;
  cin >> n >> k >> m;
  FOR (i, 0, n){
    FOR (j, 0, (1 << k)){
      dist[i][j] = INF;
    }
  }
  FOR (i, 0, k){
    int aa;
    cin >> aa;
    dist[--aa][(1<<i)] = 0;
  }
  FOR (i, 0, m){
    int aa, bb, cc;
    cin >> aa >> bb >> cc;
    adj[--aa].pb({cc, -- bb});
    adj[bb].pb({cc, aa});
  }
  for (int mask = 0; mask < (1 << k); ++ mask){
    for (int u = 0; u < n; ++ u){
      for (int sub = mask; sub; sub = (sub - 1) & mask){
        dist[u][mask] = min (dist[u][mask], dist[u][sub] + dist[u][mask^sub]);
      }
    }
    dijk (mask);
  }
  /*for (int i = 0; i < n; ++ i){
    for (int j = 0; j < (1 << k); ++ j){
      cout << dist[i][j] << " ";
    }
    cout << '\n';
  }*/
  for (int i = 0; i < n; ++ i){
    ans = min (ans, dist[i][(1<<k)-1]);
  }
  cout << ans;
  return 0;
}

// Yesterday is history
// Tomorrow is a mystery
// but today is a gift
// That is why it is called the present

• Subtask 1: 22 / 22
• Subtask 2: 0 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 26