#include<bits/stdc++.h>
using namespace std;
int n,q,root;
vector<int> con[100005];
struct node
{
int cnt0,cnt1;
int lazy;
};
node aint[270000];
void propagate(int nod)
{
if(!aint[nod].lazy)
return;
aint[nod*2].lazy ^= 1;
aint[nod*2+1].lazy ^= 1;
swap(aint[nod*2].cnt0, aint[nod*2].cnt1);
swap(aint[nod*2+1].cnt0, aint[nod*2+1].cnt1);
aint[nod].lazy=0;
}
void upd(int nod, int st, int dr, int le, int ri)
{
if(le>ri)
return;
if(le==st && dr==ri)
{
aint[nod].lazy ^= 1;
swap(aint[nod].cnt0, aint[nod].cnt1);
return;
}
propagate(nod);
int mij=(st+dr)/2;
upd(nod*2,st,mij,le,min(mij,ri));
upd(nod*2+1,mij+1,dr,max(mij+1,le),ri);
aint[nod].cnt0 = aint[nod*2].cnt0 + aint[nod*2+1].cnt0;
aint[nod].cnt1 = aint[nod*2].cnt1 + aint[nod*2+1].cnt1;
}
int siz[100005];
int cntf[100005];
int head[100005];
int parent[100005];
int depth[100005];
int pos[100005],curpos;
void dfs(int nod)
{
siz[nod]=1;
for(auto adj:con[nod])
{
if(adj!=parent[nod])
{
parent[adj]=nod;
depth[adj]=depth[nod]+1;
dfs(adj);
cntf[nod] += cntf[adj];
siz[nod] += siz[adj];
}
}
if(cntf[nod]==0) cntf[nod]=1;
}
void decompose(int nod, int chead)
{
pos[nod]=++curpos;
head[nod]=chead;
int heavy=-1,maxc=-1;
for(auto adj:con[nod])
if(adj!=parent[nod] && siz[adj]>maxc)
maxc=siz[adj], heavy=adj;
if(heavy!=-1)
decompose(heavy,chead);
for(auto adj:con[nod])
if(adj!=parent[nod] && adj!=heavy)
decompose(adj,adj);
}
void hld_upd(int a)
{
for(;head[a]!=root;a=parent[head[a]])
{
upd(1,1,n,pos[head[a]],pos[a]);
}
upd(1,1,n,pos[root],pos[a]);
}
int aux[100005];
int visited[100005];
void build(int nod, int st, int dr)
{
if(st==dr)
{
aint[nod].cnt0=1;
return;
}
int mij=(st+dr)/2;
build(nod*2,st,mij);
build(nod*2+1,mij+1,dr);
aint[nod].cnt0 = aint[nod*2].cnt0 + aint[nod*2+1].cnt0;
}
signed main()
{
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>q;
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++)
{
if((int)con[i].size()>1)
{
root=i;
break;
}
}
dfs(root);
decompose(root,root);
build(1,1,n);
for(int i=1;i<=n;i++)
if(cntf[i]%2==1)
upd(1,1,n,pos[i],pos[i]);
for(int pas=1;pas<=q;pas++)
{
int nr,auxf=0;
cin>>nr;
for(int i=1;i<=nr;i++)
{
cin>>aux[i];
hld_upd(aux[i]);
if(cntf[aux[i]]==1 && visited[aux[i]]!=pas)
visited[aux[i]]=pas;
else
auxf++;
}
if((cntf[root]+auxf)%2==1) cout<<-1<<"\n";
else cout<<aint[1].cnt0*2 + aint[1].cnt1 - 2 + nr<<"\n";
for(int i=1;i<=nr;i++)
hld_upd(aux[i]);
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
6748 KB |
Output is correct |
2 |
Incorrect |
139 ms |
8568 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
43 ms |
7516 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
36 ms |
8284 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
75 ms |
9300 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
193 ms |
11604 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
244 ms |
14204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
6748 KB |
Output is correct |
2 |
Incorrect |
139 ms |
8568 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |