Submission #695269

#	Time	Username	Problem	Language	Result	Execution time	Memory
695269		Ahmed_Solyman	Railway (BOI17_railway)	C++14	8 / 100	1089 ms	30752 KiB

railway

#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m,k;
	cin>>n>>m>>k;
	vector<int>adj[n+5];
	vector<int>a(n+5),b(n+5);
	for(int i=0;i<n-1;i++){
		int u,v;cin>>u>>v;
		a[i]=u;b[i]=v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	vector<int>vis(n+5);
	map<pair<int,int>,int>e;
	vector<int>parent(n+5);
	while(m--){
		int k;cin>>k;
		vector<int>v(k);
		for(auto &i:v)cin>>i;
		int root=v[0];
		queue<int>q;
		q.push(root);
		for(int i=0;i<n;i++)vis[i+1]=0,parent[i+1]=0;
		while(q.size()){
			int x=q.front();
			q.pop();
			vis[x]=1;
			for(auto i:adj[x]){
				if(!vis[i]){
					q.push(i);
					parent[i]=x;
				}
			}
		}
		map<pair<int,int>,bool>z;
		for(int i=1;i<k;i++){
			int u=v[i];
			while(u!=root){
				z[{u,parent[u]}]=1;
				z[{parent[u],u}]=1;
				u=parent[u];
			}
		}
		for(auto i:z){
			//cout<<i.first.first<<" : "<<i.first.second<<endl;
			e[i.first]++;
		}
	}
	vector<int>d;
	for(int i=0;i<n-1;i++){
		if(e[{a[i],b[i]}]>=k){
			d.push_back(i+1);
		}
	}
	cout<<d.size()<<endl;
	for(auto i:d)cout<<i<<" ";
}

• Subtask 1: 8 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 7
• Subtask 4: 0 / 29
• Subtask 5: 0 / 16
• Subtask 6: 0 / 25