#include <bits/stdc++.h>
#define speed ios_base::sync_with_stdio(0); cin.tie(0)
#define all(x) (x).begin(),(x).end()
#define F first
#define S second
//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx,avx2")
//#pragma GCC target("popcnt")
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const ll MAX=2e5+10,P=1e9+7;
const ll INF=0x3f3f3f3f,oo=0x3f3f3f3f3f3f3f3f;
const ldb eps=1e-6;
const ldb PI=acos(-1.0);
const int dir[4][2]={{0,1},{0,-1},{1,0},{-1,0}};
template<typename T>
using vvector = vector<vector<T>>;
void dfs(int v,int p,vvector<int> &G,vector<int> &cnt,vector<pii> &dfn,int &tm,vector<int> &dep) {
dfn[v].F=tm++;
cnt[v]=(G[v].size()<=1);
for (int i:G[v]) {
if (i==p) continue;
dep[i]=dep[v]+1;
dfs(i,v,G,cnt,dfn,tm,dep);
cnt[v]^=cnt[i];
}
// cout<<v<<" "<<cnt[v]<<" v cnt\n";
dfn[v].S=tm++;
}
int dfs2(int v,int p,vvector<int> &G,vector<int> &cnt,int &ans) {
ans+=cnt[v];
cnt[v]+=cnt[p];
int ttl=(G[v].size()==1);
for (int i:G[v]) {
if (i==p) continue;
ttl+=dfs2(i,v,G,cnt,ans);
}
return ttl;
}
struct BIT {
int n;
vector<int> a;
BIT(int n):n(n) {
a.resize(n+1);
}
void update(int x,int val) {
while (x<=n) {
a[x]+=val;
x+=(-x&x);
}
}
int query(int x) {
int ans=0;
while (x) {
ans+=a[x];
x-=(-x&x);
}
return ans;
}
};
int main() {
speed;
int n,q;
cin>>n>>q;
vvector<int> G(n+1);
for (int i=0;i<n-1;i++) {
int a,b;
cin>>a>>b;
G[a].push_back(b);
G[b].push_back(a);
}
int rt=0;
for (int i=1;i<=n;i++) {
if (G[i].size()>1) {
rt=i;
break;
}
}
vector<int> cnt(n+1),dep(n+1);
vector<pii> dfn(n+1);
int tm=1;
dfs(rt,0,G,cnt,dfn,tm,dep);
cnt[rt]=0;
int ans=0;
int tlv = dfs2(rt,0,G,cnt,ans);
BIT b(tm-1);
// cout<<rt<<" "<<ans<<" rt ans\n";
while (q--) {
int d;
cin>>d;
map<int,int> app;
for (int i=0;i<d;i++) {
int x;
cin>>x;
app[x]++;
}
vector<int> ttl;
for (auto [i,x]:app) {
if (x&1) ttl.push_back(i);
}
sort(all(ttl),[&](int a,int b) {
return dep[a]>dep[b];
});
ll dta=0;
for (int v:ttl) {
int rev = b.query(dfn[v].S)-b.query(dfn[v].F-1);
// cout<<v<<" "<<rev<<" v rev\n";
if (rev&1) dta+=2*cnt[v]-dep[v];
else dta+=dep[v]-2*cnt[v];
b.update(dfn[v].F,1);
if (G[v].size()==1) d--;
}
for (int v:ttl) b.update(dfn[v].F,-1);
// cout<<2*(n-1)<<" "<<ans<<" "<<dta<<" "<<d<<" 2*(n-1) ans dta d\n";
if ((tlv+d)&1) {
cout<<"-1\n";
continue;
}
int qans=2*(n-1)-(ans+dta)+d;
cout<<qans<<"\n";
}
return 0;
}
/*
7 3
1 2
2 4
4 5
5 6
5 7
3 4
1 4
2 2 4
1 1
*/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
336 KB |
Output is correct |
2 |
Incorrect |
32 ms |
3012 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
11 ms |
1104 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
13 ms |
2128 KB |
Output is correct |
2 |
Correct |
15 ms |
2128 KB |
Output is correct |
3 |
Correct |
47 ms |
21724 KB |
Output is correct |
4 |
Correct |
72 ms |
23332 KB |
Output is correct |
5 |
Correct |
37 ms |
19788 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
19 ms |
3932 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
42 ms |
6988 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
67 ms |
10684 KB |
Output is correct |
2 |
Incorrect |
60 ms |
15000 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
336 KB |
Output is correct |
2 |
Incorrect |
32 ms |
3012 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |