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Submission #321387

# Submission time Handle Problem Language Result Execution time Memory
321387 2020-11-12T08:36:21 Z kshitij_sodani Pastiri (COI20_pastiri) C++14
23 / 100
 1000 ms 55908 KB 
//#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
typedef long long llo;
#define mp make_pair
#define pb push_back
#define a first 
#define b second
//#define endl '\n'

int n,k;
vector<int> adj[500001];
vector<int> ans;
int lev[500001];
int par[500001][20];
int vis[500001];
int vis2[500001];
int mi[500001];
void dfs(int no,int par2=-1,int levv=0){
	lev[no]=levv;
	par[no][0]=par2;
	for(auto j:adj[no]){
		if(j!=par2){
			dfs(j,no,levv+1);
		}
	}
}
int cot=-1;
int dist[2001][2001];
void dfs2(int no,int par2=-1,int levv=0){

	dist[cot][no]=levv;
	for(auto j:adj[no]){
		if(j!=par2){
			dfs2(j,no,levv+1);
		}
	}
}
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cin>>n>>k;
	for(int i=0;i<n-1;i++){
		int aa,bb;
		cin>>aa>>bb;
		aa--;
		bb--;
		adj[aa].pb(bb);
		adj[bb].pb(aa);
	}
	vector<int> ss(k);
	for(int i=0;i<k;i++){
		cin>>ss[i];
		ss[i]--;
		vis2[ss[i]]=1;
	}
	for(int i=0;i<n;i++){
		mi[i]=n;
	}
	queue<pair<int,int>> mm;
	for(auto j:ss){
		mi[j]=0;
		mm.push({0,j});
	}
	while(mm.size()){
		pair<int,int> no=mm.front();
		mm.pop();
		for(auto j:adj[no.b]){
			if(mi[j]==n){
				mi[j]=no.a+1;
				mm.push({mi[j],j});
			}
		}
	}

	for(int i=0;i<n;i++){
		cot=i;
		dfs2(i);
	}
	

	dfs(0);
	for(int j=1;j<20;j++){
		for(int i=0;i<n;i++){
			if(par[i][j-1]==-1){
				par[i][j]=-1;
			}
			else{
				par[i][j]=par[par[i][j-1]][j-1];
			}
		}
	}

	vector<pair<int,int>> tt;
	for(auto j:ss){
		tt.pb({lev[j],j});
	}
	sort(tt.begin(),tt.end());
	/*for(int i=0;i<n;i++){
		cout<<par[i][0]<<",";
	}
	cout<<endl;
	for(int i=0;i<n;i++){
		cout<<par[i][1]<<",";
	}
	cout<<endl;
	cout<<par[19][0]<<",,"<<par[19][1]<<endl;*/
	while(tt.size()){
		if(vis[tt.back().b]){
			tt.pop_back();
			continue;
		}
		int x=tt.back().b;

		int cur=x;
		int co=0;
		for(int j=19;j>=0;j--){
			if(par[cur][j]==-1){
				continue;
			}
			if(dist[par[cur][j]][x]==mi[par[cur][j]]){
				cur=par[cur][j];
				co+=(1<<j);
			}
		}
	//	cout<<par[19][1]<<endl;
	//	cout<<x<<":"<<cur<<":"<<co<<endl;
		/*int pp=x;
		int cur=par[x][0];
		int co=1;
		while(cur!=-1){
			if(co==mi[cur]){
				pp=cur;
				cur=par[cur][0];
				co++;
				continue;
			}
			cur=par[cur][0];
			co++;
		}
		cur=pp;*/
		for(int i=0;i<k;i++){
			if(dist[cur][ss[i]]==mi[cur]){
				vis[ss[i]]=1;
			}
		}
		ans.pb(cur);
		tt.pop_back();
	}
	cout<<ans.size()<<endl;
	for(auto j:ans){
		cout<<j+1<<" ";
	}
	cout<<endl;











 
 
	return 0;
}

Subtask #1
0 / 8.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1061 ms 55908 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #2
0 / 18.0

# Verdict Execution time Memory Grader output
1 Incorrect 532 ms 51396 KB Integer 0 violates the range [1, 5000]
2 Halted 0 ms 0 KB -

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 82 ms 28132 KB Output is correct
2 Correct 80 ms 28004 KB Output is correct
3 Correct 81 ms 28004 KB Output is correct
4 Correct 55 ms 24932 KB Output is correct
5 Correct 86 ms 28132 KB Output is correct
6 Correct 90 ms 28132 KB Output is correct
7 Correct 96 ms 27620 KB Output is correct
8 Correct 93 ms 27620 KB Output is correct
9 Correct 57 ms 28004 KB Output is correct
10 Correct 56 ms 28004 KB Output is correct
11 Correct 38 ms 22884 KB Output is correct
12 Correct 27 ms 20204 KB Output is correct
13 Correct 69 ms 26468 KB Output is correct
14 Correct 96 ms 28132 KB Output is correct
15 Correct 88 ms 28036 KB Output is correct

Subtask #4
0 / 51.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1025 ms 34784 KB Time limit exceeded
2 Halted 0 ms 0 KB -