Submission #815387

#	Time	Username	Problem	Language	Result	Execution time	Memory
815387		NguyenKhang	Bosses (BOI16_bosses)	C++17	100 / 100	928 ms	980 KiB

bosses

//#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC target("bmi,bmi2,lzcnt,popcnt")
//#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
//#pragma expected_value
//#pragma isolated_call
//#pragma disjoint

#include<bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>

//using namespace __gnu_pbds;
using namespace std;

//#define int long long
//#define double long double
#define Fi first
#define Se second
#define Rep(i,a,b) for (int i=a;i<=b;++i)
#define Repu(i,b,a) for (int i=b;i>=a;--i)
#define pb push_back
#define ms(a,i) memset(a,i,sizeof(a))
#define sz size()
#define mp make_pair
#define endl '\n'
#define sef setprecision(6)<<fixed
#define cer cout<<"cak"<<endl;

typedef pair<int,int> ii;
typedef vector<int> vi;
typedef vector<double> va;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<va> vva;

//const double EPS=1e-9;
const double PI=acos(-1);
const long long oo=1e18;
const int MN=5000+5;
const int mod=1e9+7;

using cd=complex<double>;

//typedef tree<int,null_type,less<int>,rb_tree_tag, tree_order_statistics_node_update> index_set;

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

int n;
vi adj[MN];

int visited[MN];
vi G[MN];
int dp[MN];

int res;

bool bfs(int x) {
	res = 0;
	Rep(i,1,n) {
		visited[i] = 0;
		dp[i] = 0;
		G[i].clear();
	}
	queue<int> Q; Q.push(x);
	visited[x] = 1;

	int comp = n-1;

	while(!Q.empty()) {
		int u = Q.front(); Q.pop();
		for(int v:adj[u]) {
			if(visited[v]) continue;
			comp--;
			visited[v] = 1;
			Q.push(v); G[u].pb(v);
		}
	}

	return (comp == 0);
}

void solve(int u,int pre) {
	dp[u] = 1;
	for(int v:G[u]) {
		if(v==pre) continue;
		solve(v,u);
		dp[u] += dp[v];
	}
	res += dp[u];
}

signed main() {
  	//freopen(".inp","r",stdin); freopen(".out","w",stdout);
  	
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);

	cin>>n;
	Rep(i,1,n) {
		int k; cin>>k;
		while(k--) {
			int x; cin>>x;
			adj[x].pb(i);
		}
	}

	// root
	int ans = mod;
	Rep(root,1,n) {
		if(!bfs(root)) continue;
		solve(root,root);
		ans = min(ans,res);
	}

	cout<<ans;
}

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