Submission #813370

#	Time	Username	Problem	Language	Result	Execution time	Memory
813370		SteGG	Bosses (BOI16_bosses)	C++17	100 / 100	1118 ms	980 KiB

bosses

#include <bits/stdc++.h>
#define int long long

using namespace std;

void open(){
	if(fopen("input.inp", "r")){
		freopen("input.inp", "r", stdin);
		// freopen("output.out", "w", stdout);
	}
}

const int inf = 3e18;
const int maxn = 5005;
int n;
vector<int> candidate[maxn];
vector<int> tr[maxn];
bool check[maxn];

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	open();
	cin >> n;
	for(int i = 1; i <= n; i++){
		int k;
		cin >> k;
		for(int j = 1; j <= k; j++){
			int a;
			cin >> a;
			candidate[a].push_back(i);
		}
	}

	int result;
	int last_result = inf;

	auto dfs = [&](auto &&dfs, int u) -> int {
		int sz = 1;
		for(int v : tr[u]){
			sz += dfs(dfs, v);
		}

		result += sz;
		return sz;
	};

	for(int root = 1; root <= n; root++){
		memset(check, false, sizeof(check));
		for(int i = 0; i <= n; i++){
			tr[i].clear();
		}

		queue<pair<int, int>> q;
		q.push({root, 0});
		int cnt = 0;
		while(!q.empty()){
			int u = q.front().first;
			int p = q.front().second;
			q.pop();
			if(check[u]) continue;
			cnt++;
			check[u] = true;
			tr[p].push_back(u);
			for(int v : candidate[u]){
				if(check[v]) continue;
				q.push({v, u});
			}
		}

		if(cnt < n) continue;

		result = 0;

		dfs(dfs, root);
		last_result = min(result, last_result);
	}


	cout << last_result << endl;

	return 0;
}

Compilation message (stderr)

bosses.cpp: In function 'void open()':
bosses.cpp:8:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |   freopen("input.inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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