Submission #1087911

#	Time	Username	Problem	Language	Result	Execution time	Memory
1087911		4QT0R	Bitaro’s Party (JOI18_bitaro)	C++17	0 / 100	7 ms	8028 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>

vector<pii> best[100003];
vector<int> graph[100003];
vector<int> rev[100003];
bool aval[100003];
int vis[100003];
int dp[100003];

const int siz=300;

int dfs(int v){
	dp[v]=0;
	int ans=1e9;
	for (auto u : rev[v]){
		ans=min(ans,dfs(u));
		dp[v]=max(dp[v],dp[u]+1);
	}
	return aval[v]?ans:min(dp[v],ans);
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	int n,m,q;
	cin >> n >> m >> q;
	for (int i = 1,s,t; i<=m; i++){
		cin >> s >> t;
		graph[s].push_back(t);
		rev[t].push_back(s);
	}
	priority_queue<pii> pq;
	for (int i = 1; i<=n; i++){
		pq.push({0,i});
		for (auto u : rev[i]){
			for (auto [v,d] : best[u]){
				pq.push({d+1,v});
			}
		}
		for (;best[i].size()<=siz && pq.size();pq.pop()){
			auto [d,v] = pq.top();
			if (vis[v]!=i){
				vis[v]=i;
				best[i].push_back({v,d});
			}
		}
		for(;pq.size();pq.pop());
	}

	vector<int> wej;
	for (int i = 1,fin,num; i<=q; i++){
		cin >> fin >> num;
		for (int j = 0,v; j<num; j++){
			cin >> v;
			wej.push_back(v);
		}
		for (auto u : wej)aval[u]=true;
		if (num>=siz){
			int wyn=dfs(fin);
			if (wyn==1e9)cout << "-1\n";
			else cout << dp[fin]-wyn << '\n';
		}
		else{
			int ans=-1;
			for (auto [u,d] : best[fin]){
				if (!aval[u])ans=max(ans,d);
			}
			cout << ans << '\n';
		}
		for (auto u : wej)aval[u]=false;
		wej.clear();
	}
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86