Submission #636977

#	Time	Username	Problem	Language	Result	Execution time	Memory
636977		Cyber_Wolf	Bosses (BOI16_bosses)	C++14	100 / 100	937 ms	6924 KiB

bosses

//Contest: BOI 2016 Day 1 Problem 1
//Problem: Bosses

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("Ofast")

using namespace std;
using namespace __gnu_pbds;

#define lg long long
#define ordered_set	tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define error(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args);
#define endl \n
#define lbound(x, y) lower_bound(x.begin(), x.end(), y) 
#define ubound(x, y) upper_bound(x.begin(), x.end(), y) 
#define sortasc(v) sort(v.begin(), v.end())	
#define sortdesc(v) sort(v.rbegin(), v.rend())	
#define custom_array(a,l, r) int _##a[r-l+1]; int*a=_##a-l;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const lg MOD = 1e9+7, N = 2e5+5, M = 1e7+1, SZ = 1e3+1;
/*
bitset<N> primes;
lg pwrs[N], inv[N];

lg fast_power(lg n, lg k)
{
	if(!k)	return 1;
	if(k&1)	return (fast_power(n, k-1)*n)%MOD;
	lg x = fast_power(n, k/2)%MOD;
	return (x*x)%MOD;
}

void sieve()
{
	primes.set();
	primes[0] = primes[1] = 0;
	for(lg i = 2; i < N; i++)
	{
		if(!primes[i])	continue;
		for(lg j = i*i; j < N; j += i)
		{
			primes[j] = 0;
		}
	}
	return;
}

struct matrix
{
	vector<vector<lg>> con = vector<vector<lg>> (SZ, vector<lg> (SZ));
	matrix operator *(const matrix& a)
	{
		matrix product;
		for(int i = 0; i < (lg)con.size(); i++)
		{
			for(int j = 0; j < (lg)a.con[0].size(); j++)
			{
				for(int k = 0; k < (lg)a.con.size(); k++)
				{
					product.con[i][j] = (product.con[i][j]+(con[i][k]*a.con[k][j])%MOD)%MOD; 
				}
			}
		}
		return product;
	}
};

void preprocess(lg x)
{
	inv[2e5] = fast_power(x, MOD-2);
	for(int i = 2e5-1; i > 1; i--)
	{
		inv[i] = (inv[i+1]*i)%MOD;
	}
	pwrs[0] = 1;
	for(int i = 1; i <= 2e5; i++)
	{
		pwrs[i] = (pwrs[i]*i)%MOD;
	}
	return;
}

*/

vector<lg> adj[N];
lg vis[N], tmp, dist[N], n;

lg bfs(lg src)
{
	vis[src] = tmp;
	queue<lg> q;
	q.push(src);
	memset(dist, 0, sizeof(dist));
	dist[src] = 1;
	lg dis = 1;
	while(q.size())
	{
		dis++;
		lg sz = q.size();
		while(sz--)
		{
			lg u = q.front();
			q.pop();
			for(auto it : adj[u])
			{
				if(vis[it] == tmp)	continue;
				vis[it] = tmp;
				dist[it] = dis;
				q.push(it);
			}
		}
	}
	lg ans = 0;
	for(int i = 1; i <= n; i++)	
	{
		ans += dist[i];
	}
	return ans;
}

int main()
{
	fastio;
	cin >> n;
	for(int i = 1; i <= n; i++)
	{
		lg k;
		cin >> k;
		while(k--)
		{
			lg x;
			cin >> x;
			adj[x].push_back(i);
		}
	}
	lg ans = LLONG_MAX;
	for(int i = 1; i <= n; i++)
	{
		tmp++;
		lg cur = bfs(i);
		bool flag = true;
		for(int j = 1; j <= n; j++)
		{
			flag &= (vis[j] == tmp);
		}
		if(flag)	ans = min(ans, cur);
	}
	cout << ans << '\n';
	
    return 0;
}

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