Submission #1126531

#	Time	Username	Problem	Language	Result	Execution time	Memory
1126531		ntdaccode	Cities (BOI16_cities)	C++20	74 / 100	6098 ms	165764 KiB

cities

#include<bits/stdc++.h>

using namespace std;
const int M = 1e5 + 10;
int n,m,k;
long long  f[M][1 << 5];
vector<pair<int,int>> ke[M];
priority_queue<tuple<long long ,int ,int >,vector<tuple<long long ,int ,int > > ,greater<tuple<long long ,int ,int > > > h;

vector<int> submask[1 << 5][1 << 5];
long long  kq=1e18;
int dd[M];
void dij()
{
  while(!h.empty())
  {
    auto [val,mask,u] = h.top();h.pop();
    if(val >= kq) {
      cout << kq;
      exit(0);
    }
    if(f[u][mask] != val) continue;

    for(pair<int,int> v : ke[u])
    {
      dd[v.first] = (mask | dd[v.first]);
      for(int i : submask[mask][dd[v.first]])
      {
        if(val + f[v.first][i^mask] + v.second < f[v.first][i])
        {
          f[v.first][i] = val + f[v.first][i^mask] + v.second;
          if(i != (1<<k) - 1) h.push({f[v.first][i], i, v.first});
          else kq = min(kq, f[v.first][i]);
        }
      }
    }
  }
}
int32_t main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  #define task "1"
  if(fopen(task".inp","r"))
  {
    freopen(task".inp","r",stdin);
    freopen(task".out","w",stdout);
  }
  cin >> n >> k >> m;
  for(int i = 0;i < (1 << k); i++)
  {
    for(int e = 0;e < (1 << k); e++) {
    for(int j = (1 << k) - 1;j >= 0; j--) if((i & j) == i && (j & e) == j) submask[i][e].push_back(j);
    }
  }
  for(int i = 1;i <= n; i++)
  {
    for(int j = 1;j < (1 << k); j++) f[i][j] = 1e18;
  }

  for(int i = 0;i < k; i++)
  {
    int x;
    cin >> x;
    h.push({0,1 << i,x});
    f[x][1 << i] = 0;
    dd[x] = 1 << i;
  }
  for(int i = 1;i <= m; i++)
  {
    int u,v;
    long long w;
    cin >> u >> v >> w;
    ke[u].push_back({v,w});
    ke[v].push_back({u,w});
  }
  dij();
}

Compilation message (stderr)

cities.cpp: In function 'int32_t main()':
cities.cpp:47:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |     freopen(task".inp","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
cities.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     freopen(task".out","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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