#include<bits/stdc++.h>
using namespace std;
#define int long long
const int INF = 1e9;
int n,k;
vector<int> con[500005];
int closest[500005];
int mind[500005];
int depth[500005];
bool isoaie[500005];
vector<int> sol;
void dfs_sterge(int nod, int par, int d)
{
if(d==0)
{
isoaie[nod]=0;
return;
}
for(auto adj:con[nod])
if(adj!=par)
dfs_sterge(adj,nod,d-1);
}
void sterge(int x, int d)
{
dfs_sterge(x,0,d);
}
void dfs(int nod, int par)
{
mind[nod]=INF;
if(closest[nod]==0) mind[nod]=depth[nod];
for(auto adj:con[nod])
{
if(adj==par)
continue;
depth[adj]=depth[nod]+1;
dfs(adj,nod);
mind[nod] = min(mind[nod], mind[adj]);
}
}
bool cmp(int x, int y)
{
return mind[x] > mind[y];
}
set<int> s[500005];
bool gata[500005];
void dfs2(int nod, int par)
{
sort(con[nod].begin(),con[nod].end(),cmp);
bool rau=0;
for(auto adj:con[nod])
{
if(adj==par || mind[adj]==INF)
continue;
dfs2(adj,nod);
if(s[nod].find(2*depth[nod]-mind[nod])!=s[nod].end())
gata[adj]=1;
if((int)s[adj].size() > (int)s[nod].size())
swap(s[adj],s[nod]);
for(auto x:s[adj])
s[nod].insert(x);
if(gata[adj])
continue;
if(mind[adj]!=mind[nod] || mind[nod]-depth[nod] > closest[nod])
{
sol.push_back(adj);
///sterge(adj,closest[adj]);
s[nod].insert(depth[adj]-closest[adj]);
gata[adj]=1;
}
else
rau=1;
}
if(mind[nod]==INF)
{
gata[nod]=1;
return;
}
if(closest[nod]==0 && s[nod].find(2*depth[nod]-mind[nod])!=s[nod].end())
{
gata[nod]=1;
return;
}
if(mind[nod]-depth[nod] > closest[nod])
{
gata[nod]=1;
return;
}
if(closest[nod]==0)
rau=1;
if(!rau)
{
gata[nod]=1;
return;
}
if(mind[nod]-depth[nod]==closest[nod] && (nod==1 || mind[nod]-depth[par]!=closest[par]))
{
//cout<<nod<<" sters nod\n";
sol.push_back(nod);
///sterge(nod,closest[nod]);
s[nod].insert(depth[nod]-closest[nod]);
gata[nod]=1;
}
}
signed main()
{
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>k;
int u,v;
for(int i=1;i<n;i++)
{
cin>>u>>v;
con[u].push_back(v);
con[v].push_back(u);
}
for(int i=1;i<=n;i++)
closest[i]=INF;
deque<int> dq;
for(int i=1;i<=k;i++)
{
cin>>u;
isoaie[u]=1;
closest[u]=0;
dq.push_back(u);
}
while(!dq.empty())
{
int nod = dq.front();
dq.pop_front();
for(auto adj:con[nod])
{
if(closest[adj] > closest[nod]+1)
{
closest[adj] = closest[nod]+1;
dq.push_back(adj);
}
}
}
depth[1]=1;
dfs(1,0);
dfs2(1,0);
cout<<sol.size()<<"\n";
for(auto x:sol)
cout<<x<<" ";
return 0;
}
/**
depth[x] - closest[x] = 2*depth[nod] - mind[nod]
*/
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
151 ms |
102844 KB |
Output is correct |
2 |
Correct |
216 ms |
149844 KB |
Output is correct |
3 |
Correct |
217 ms |
149840 KB |
Output is correct |
4 |
Correct |
320 ms |
164744 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
42276 KB |
Output is correct |
2 |
Correct |
10 ms |
42076 KB |
Output is correct |
3 |
Correct |
320 ms |
67304 KB |
Output is correct |
4 |
Correct |
315 ms |
72240 KB |
Output is correct |
5 |
Correct |
410 ms |
64304 KB |
Output is correct |
6 |
Correct |
584 ms |
71868 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
42076 KB |
Output is correct |
2 |
Correct |
11 ms |
42164 KB |
Output is correct |
3 |
Correct |
11 ms |
42076 KB |
Output is correct |
4 |
Correct |
11 ms |
42076 KB |
Output is correct |
5 |
Correct |
9 ms |
42076 KB |
Output is correct |
6 |
Correct |
10 ms |
42076 KB |
Output is correct |
7 |
Correct |
10 ms |
42076 KB |
Output is correct |
8 |
Correct |
9 ms |
42076 KB |
Output is correct |
9 |
Correct |
10 ms |
42076 KB |
Output is correct |
10 |
Correct |
9 ms |
42076 KB |
Output is correct |
11 |
Correct |
9 ms |
42076 KB |
Output is correct |
12 |
Correct |
9 ms |
42076 KB |
Output is correct |
13 |
Correct |
10 ms |
42076 KB |
Output is correct |
14 |
Correct |
9 ms |
42076 KB |
Output is correct |
15 |
Correct |
10 ms |
42076 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
427 ms |
69284 KB |
Output is correct |
2 |
Correct |
468 ms |
68652 KB |
Output is correct |
3 |
Correct |
535 ms |
73288 KB |
Output is correct |
4 |
Correct |
611 ms |
64380 KB |
Output is correct |
5 |
Correct |
420 ms |
67804 KB |
Output is correct |
6 |
Correct |
547 ms |
78444 KB |
Output is correct |
7 |
Correct |
555 ms |
77600 KB |
Output is correct |
8 |
Correct |
548 ms |
77816 KB |
Output is correct |
9 |
Correct |
584 ms |
64700 KB |
Output is correct |
10 |
Correct |
456 ms |
67700 KB |
Output is correct |
11 |
Correct |
321 ms |
73536 KB |
Output is correct |
12 |
Correct |
362 ms |
75304 KB |
Output is correct |
13 |
Correct |
352 ms |
77432 KB |
Output is correct |
14 |
Correct |
288 ms |
74332 KB |
Output is correct |
15 |
Correct |
46 ms |
50004 KB |
Output is correct |
16 |
Correct |
533 ms |
66956 KB |
Output is correct |
17 |
Correct |
362 ms |
72248 KB |
Output is correct |
18 |
Correct |
445 ms |
64592 KB |
Output is correct |
19 |
Correct |
510 ms |
84808 KB |
Output is correct |
20 |
Correct |
546 ms |
95400 KB |
Output is correct |
21 |
Correct |
396 ms |
70196 KB |
Output is correct |
22 |
Correct |
417 ms |
71548 KB |
Output is correct |