Submission #388236

#	Time	Username	Problem	Language	Result	Execution time	Memory
388236		soroush	Bosses (BOI16_bosses)	C++17	100 / 100	1182 ms	908 KiB

bosses

//*
//#pragma GCC optimize("O2")
#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("avx,avx2,sse,sse2,fma")
//*/
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int , int> pii;

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

const int maxn = 5010;
const ll mod = 1e9+7;
const ld PI = acos((ld)-1);

#define pb push_back
#define endl '\n'
#define dokme(x) cout << x , exit(0)
#define migmig ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define ms(x , y) memset(x , y , sizeof x)
ll pw(ll a, ll b, ll md = mod){ll res = 1;while(b){if(b&1){res=(a*res)%md;}a=(a*a)%md;b>>=1;}return(res);}

int n;
vector < int > in[maxn];
bool mark[maxn];
int sz[maxn];
int q[maxn] , l , r;
vector < int > adj[maxn];

void dfs(int v){
	sz[v] = 1;
	for(auto u : adj[v])
		dfs(u) , sz[v] += sz[u];
}

int solve(int v){
	l = r = 0;
	ms(mark , 0);
	for(int i = 1 ; i <= n ; i ++)adj[i].clear();
	q[r++] = v;
	mark[v] = 1;
	int cnt = 1;
	while(l < r){
		int v = q[l++];
		for(auto u : in[v])if(!mark[u])
			mark[u] = 1, cnt++ , q[r++] = u , adj[v].pb(u);
	}
	if(cnt ^ n)return 1e9;
	dfs(v);
	int ans = 0;
	for(int i = 1 ; i <= n ; i ++)ans += sz[i];
	return ans;
}

int32_t main(){
	migmig;
	cin >> n;
	for(int i = 1 ; i <= n ; i ++){
		int k;
		cin >> k;
		for(int j = 0 ; j < k ; j ++){
			int v;
			cin >> v;
			in[v].pb(i);
		}
	}
	//in-tree , sigma sz[v] min she
	int ans = 1e9;
	for(int i = 1 ; i <= min(n, 2500) ; i ++)
		ans = min(ans , solve(i));
	for(int i = n ; i >= 3500 ; i --)
		ans = min(ans , solve(i));
	cout << ans;
	return(0);
}

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