Submission #971894

#	Time	Username	Problem	Language	Result	Execution time	Memory
971894		happy_node	Jail (JOI22_jail)	C++17	72 / 100	1695 ms	1048576 KiB

jail

#include <bits/stdc++.h>
using namespace std;

const int MX=4e5+5;
int Q,N,M;
int S[MX], T[MX];

vector<int> path[MX]; // store the path between Si and Ti

vector<int> adj[MX];

int par[MX], dep[MX];

void dfs(int v, int p) {
	par[v]=p;
	for(auto u:adj[v]) {
		if(u==p) continue;
		dep[u]=dep[v]+1;
		dfs(u,v);
	}
}

vector<int> ADJ[MX];
int deg[MX];

bool f(int i, int x) {
	for(auto y:path[i]) 
		if(y==x) return true;
	return false;
}

int cntT[MX], cntS[MX];

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

	cin>>Q;

	while(Q--) {
		cin>>N;
		for(int i=1;i<=N;i++) adj[i].clear(), cntT[i]=0, cntS[i]=0, dep[i]=0, par[i]=0;

		for(int i=0;i<N-1;i++) {
			int u,v;
			cin>>u>>v;
			adj[u].push_back(v);
			adj[v].push_back(u);
		}

		cin>>M;
		for(int i=0;i<2*N+M;i++) path[i].clear(), ADJ[i].clear(), deg[i]=0;

		dep[1]=1;
		dfs(1,0);

		for(int i=0;i<M;i++) {
			cin>>S[i]>>T[i];

			vector<int> L,R;

			int u=S[i],v=T[i];

			while(dep[u]>dep[v]) {
				L.push_back(u);
				u=par[u];
			}

			while(dep[v]>dep[u]) {
				R.push_back(v);
				v=par[v];
			}

			while(u!=v) {
				L.push_back(u);
				R.push_back(v);
				u=par[u];
				v=par[v];
			}

			for(auto x:L) path[i].push_back(x);
			path[i].push_back(u);
			reverse(R.begin(),R.end());
			for(auto x:R) path[i].push_back(x);
		}

		for(int i=0;i<M;i++) {
			cntS[S[i]]+=1;
			cntT[T[i]]+=1;
		}

		for(int i=0;i<M;i++) {
			cntS[S[i]]-=1;
			cntT[T[i]]-=1;

			for(auto x:path[i]) {
				if(cntS[x]) {
					ADJ[M-1+x].push_back(i);
					deg[i]+=1;
				}
				if(cntT[x]) {
					ADJ[i].push_back(M-1+x+N);
					deg[M-1+x+N]+=1;
				}
			}

			ADJ[i].push_back(M-1+S[i]);
			deg[M-1+S[i]]+=1;

			ADJ[M-1+T[i]+N].push_back(i);
			deg[i]+=1;

			cntS[S[i]]+=1;
			cntT[T[i]]+=1;
		}

		queue<int> q;

		for(int i=0;i<2*N+M;i++) {
			if(!deg[i]) {
				q.push(i);
			}
		}

		int ans=0;
		while(!q.empty()) {
			auto v=q.front(); q.pop();
			ans+=1;
			for(auto u:ADJ[v]) {
				deg[u]--;
				if(!deg[u]) q.push(u);
			}
		}

		cout<<(ans==2*N+M?"Yes":"No")<<'\n';
	}


}

• Subtask 1: 0 / 5
• Subtask 2: 5 / 5
• Subtask 3: 16 / 16
• Subtask 4: 28 / 28
• Subtask 5: 12 / 12
• Subtask 6: 11 / 11
• Subtask 7: 0 / 23