Submission #884270

#	Time	Username	Problem	Language	Result	Execution time	Memory
884270		vjudge1	Bosses (BOI16_bosses)	C++17	100 / 100	428 ms	820 KiB

bosses

/// I'm only brave when I have to be
#include <bits/stdc++.h>
#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;

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> >;

constexpr int MOD = 1e9 + 7, N = 5008, M = 3e5 + 8, SQ = 500, INF = 1e9 + 8, LGN = 11, mod = 998244353;

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

int n, h[N], hs[N], ans = INF;
vector <int> v[N];

void bfs (int u){
  queue <int> q;
  fill (h, h + n + 3, INF);
  fill (hs, hs + n + 3, 0);
  h[u] = 0;
  q.push(u);
  while (q.size()){
    int x = q.front();
    q.pop();
    for (int i : v[x]){
      if (h[i] > h[x] + 1){
        h[i] = h[x] + 1;
        q.push(i);
      }
    }
  }
  for (int i = 0; i < n; ++ i){
    if (h[i] == INF){
      return;
    }
    ++ hs[h[i]];
  }
  int ret = 0, ps = 0;
  for (int i = n; i >= 0; -- i){
    ps += hs[i];
    ret += ps;
  }
  ans = min (ans, ret);
  return;
}

int32_t main(){
  fast_io;
  cin >> n;
  FOR (i, 0, n){
    int m;
    cin >> m;
    FOR (j, 0, m){
      int aa;
      cin >> aa;
      v[--aa].pb(i);
    }
  }
  FOR (i, 0, n){
    bfs (i);
  }
  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: 45 / 45
• Subtask 3: 33 / 33