Submission #1040006

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040006		khanhtb	Bosses (BOI16_bosses)	C++14	100 / 100	395 ms	5212 KiB

bosses

#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define pf push_front
#define vi vector<ll>
#define vii vector<vi>
#define pll pair<ll, ll>
#define vpll vector<pll>
#define all(a) a.begin(), a.end()
#define fi first
#define se second
using namespace std;
const ll mod = 998244353; 
const ll inf = 1e18;
const ll blocksz = 320;
const ll N = 2e5+8;
int n;
vector<int> g[N];
ll bfs(ll root){
  queue<ll>qu; ll res = 0;
  vector<ll>h(n+1,0); vector<bool>vis(n+1,false); 
  h[root] = 1; qu.push(root); vis[root] = true; 
  while(!qu.empty()){
    ll u = qu.front(); qu.pop();
    res += h[u]; 
    for(int v : g[u]){
      if(vis[v]) continue; 
      h[v] = h[u] + 1; 
      vis[v] = true;
      qu.push(v);
    }
  }
  bool flag = true; 
  for(ll i = 1;i <= n;++i) flag &= vis[i]; 
  return (flag ? res : inf);
}
void solve(){
    cin >> n;
    for(int i = 1; i <= n; i++){
        int k;cin >> k;
        for(int j = 1; j <= k; j++){
            int p;cin >> p;
            g[p].pb(i);
        }
    }
    ll ans = inf;
    for(int i = 1; i <= n; i++){
        ans = min(ans,bfs(i));
    }
    cout << ans;
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen("test.inp", "r")) {
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }
    int T = 1;
    // cin >> T;
    for (int i = 1; i <= T; i++) {
        solve();
        cout << '\n';
    }
}

Compilation message (stderr)

bosses.cpp: In function 'int main()':
bosses.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bosses.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 45 / 45
• Subtask 3: 33 / 33