Submission #743126

#	Time	Username	Problem	Language	Result	Execution time	Memory
743126		hmm789	Viruses (BOI20_viruses)	C++14	0 / 100	1 ms	452 KiB

Viruses

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF 9223372036854775807

vector<vector<int>> adj2[100];
set<int> adj[100];
int ans[100];
bool v[100];

bool cyc(int x) {
	if(v[x]) return true;
	v[x] = 1;
	for(int i : adj[x]) {
		bool f = cyc(i);
		//~ cout << "a " << x << " " << i << " " << f << endl;
		if(f) return true;
	}
	v[x] = 0;
	return false;
}

int dp(int x) {
	if(x == 0 || x == 1) return 1;
	if(ans[x] != -1) return ans[x];
	ans[x] = INF;
	for(vector<int> v : adj2[x]) {
		int tmp = 0;
		for(int i : v) {
			tmp += dp(i);
		}
		ans[x] = min(ans[x], tmp);
	}
	return ans[x];
}
		

int32_t main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	int g, n, m, x, y, a;
	cin >> g >> n >> m;
	for(int i = 0; i < n; i++) {
		cin >> x >> a;
		vector<int> tmp;
		for(int j = 0; j < a; j++) {
			cin >> y;
			adj[x].insert(y);
			tmp.push_back(y);
		}
		adj2[x].push_back(tmp);
	}
	memset(ans, -1, sizeof(ans));
	for(int i = 0; i < g; i++) {
		memset(v, 0, sizeof(v));
		if(cyc(i)) ans[i] = -2;
	}
	for(int i = 2; i < g; i++) {
		if(dp(i) == -2) cout << "YES\n";
		else cout << "NO " << dp(i) << '\n';
	}
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 14
• Subtask 3: 0 / 25
• Subtask 4: 0 / 32
• Subtask 5: 0 / 18