#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<unordered_map>
#include <queue>
#include<cstring>
#include <cassert>
#include<limits.h>
#include<cmath>
#include<set>
#include<algorithm>
#include<bitset>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;
#define ll long long
#define f first
#define endl "\n"
#define s second
#define pii pair<int,int>
#define ppii pair<int,pii>
#define vi vector<int>
#define pb push_back
//#define p push
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F(n) for(int i=0;i<n;i++)
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
using namespace std;
#pragma GCC optimize ("03,unroll-loops")
#define int long long
const int mxn=1e5+5,inf=1e9,lg=30,mod=1e9+7;
int n,q;
vector<int>adj[mxn+10];
int val[mxn+10],up[mxn+10],cnt=0;
bool leaf[mxn+10],yes[mxn+10];
int tin[mxn+10],tout[mxn+10],hvychild[mxn+10],hvypa[mxn+10],sz[mxn+10],rev[mxn+10];
int t=0;
int pos[mxn+10];
void dfs(int cur,int p){
sz[cur]=1;
for(auto i:adj[cur]){
if(i==p)continue;
dfs(i,cur);
up[i]=cur;
val[cur]+=val[i];
sz[cur]+=sz[i];
}
if(val[cur]==0||val[cur]%2)val[cur]=1;
else val[cur]=2;
if(cur==1)val[cur]=0;
}
void hld(int cur,int p){
tin[cur]=t++;
rev[tin[cur]]=cur;
if(p!=-1&&hvychild[p]==cur)hvypa[cur]=hvypa[p];
else hvypa[cur]=cur;
for(auto i:adj[cur])if(i!=p&&sz[hvychild[cur]]<sz[i])hvychild[cur]=i;
if(hvychild[cur])hld(hvychild[cur],cur);
for(auto i:adj[cur])if(i!=p&&i!=hvychild[cur])hld(i,cur);
}
struct seg{
int v1[4*mxn+10],v2[4*mxn+10];
bool lazy[4*mxn+10];
void push(int l,int r,int node){
if(!lazy[node])return;
swap(v1[node],v2[node]);
if(l!=r)lazy[node<<1]=lazy[(node<<1)^1]=true;
lazy[node]=false;
}
void update(int l,int r,int node,int ql,int qr){
push(l,r,node);
if(l>qr||r<ql)return;
if(ql<=l&&r<=qr){
lazy[node]=true;
push(l,r,node);
return;
}
int mid=l+(r-l)/2;
update(l,mid,node<<1,ql,qr);
update(mid+1,r,(node<<1)^1,ql,qr);
v1[node]=v1[node<<1]+v1[(node<<1)^1];
v2[node]=v2[node<<1]+v2[(node<<1)^1];
}
void build(int l,int r,int node){
if(l==r){
if(val[rev[l]]==1)v1[node]++;
else if(val[rev[l]]==2)v2[node]++;
return;
}
int mid=l+(r-l)/2;
build(l,mid,node<<1);
build(mid+1,r,(node<<1)^1);
v1[node]=v1[node<<1]+v1[(node<<1)^1];
v2[node]=v2[node<<1]+v2[(node<<1)^1];
}
}st;
void solve(int cur){
while(hvypa[cur]!=1){
st.update(0,n-1,1,tin[hvypa[cur]],tin[cur]);
cur=up[hvypa[cur]];
}
st.update(0,n-1,1,tin[hvypa[cur]],tin[cur]);
}
int32_t main(){
fastio
cin>>n>>q;
for(int i=0;i<n-1;i++){
int a,b;cin>>a>>b;
adj[a].pb(b);
adj[b].pb(a);
}
for(int i=1;i<=n;i++){
if(adj[i].size()==1){
leaf[i]=true;
if(i!=1)val[i]++;
cnt++;
}
}
dfs(1,-1);
hld(1,-1);
st.build(0,n-1,1);
while(q--){
int m;cin>>m;
vector<int>v(m);
for(int i=0;i<m;i++){
cin>>v[i];
if(!leaf[v[i]]||yes[v[i]])solve(v[i]),cnt++;
else yes[v[i]]=true;
}
for(auto i:v)yes[i]=false;
cout<<((cnt%2)?-1:st.v1[1]+(2*st.v2[1])+m)<<'\n';
for(auto i:v){
if(!leaf[i]||yes[i])solve(i),cnt--;
else yes[i]=true;
}
for(auto i:v)yes[i]=false;
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
8536 KB |
Output is correct |
2 |
Incorrect |
67 ms |
10588 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
34 ms |
9048 KB |
Output is correct |
2 |
Correct |
34 ms |
9052 KB |
Output is correct |
3 |
Correct |
25 ms |
16528 KB |
Output is correct |
4 |
Correct |
47 ms |
16592 KB |
Output is correct |
5 |
Correct |
48 ms |
18128 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
31 ms |
9820 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
49 ms |
11356 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
83 ms |
15188 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
120 ms |
17772 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
8536 KB |
Output is correct |
2 |
Incorrect |
67 ms |
10588 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |