#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<=(b);i++)
#define FOD(i,a,b) for (int i=(a);i>=(b);i--)
#define bit(x,y) ((x)>>(y))&1
#define pb push_back
#define ll long long
#define ii pair < int,int >
#define f first
#define s second
#define M 1000000007
#define N 100005
using namespace std;
int n,q,pos[N],numchild[N],head[N],depth[N],dad[N],numleaf[N],leaf=0,Time=0;
char tv;
vector < int > adj[N];
struct seg {
int cnt0,cnt1,lazy;
} T[4*N];
void dfs (int u,int par) {
dad[u]=par;
numchild[u]=1;
int posmax=0,maxchild=0;
FOR(i,0,adj[u].size()-1) {
int v=adj[u][i];
if (v!=par) {
dfs(v,u);
numchild[u]+=numchild[v];
numleaf[u]+=numleaf[v];
posmax = (numchild[v]>maxchild) ? i : posmax;
maxchild = (numchild[v]>maxchild) ? numchild[v] : maxchild;
}
}
swap(adj[u][0],adj[u][posmax]);
if (numchild[u]==1) {
++leaf;
numleaf[u]=1;
}
}
int node[N];
void HLD (int u) {
pos[u]=++Time;
node[Time]=u;
for (auto v : adj[u])
if (dad[v]==u) {
if (numchild[v]*2>=numchild[u]) {
head[v]=head[u];
depth[v]=depth[u];
}
else {
head[v]=v;
depth[v]=depth[u]+1;
}
HLD(v);
}
}
void Build(int id,int l,int r) {
if (l==r) {
T[id].cnt0=(numleaf[node[l]]%2==0);
T[id].cnt1=(numleaf[node[l]]%2==1);
T[id].lazy=0;
return;
}
int mid=(l+r)/2;
Build(id*2,l,mid);
Build(id*2+1,mid+1,r);
T[id].cnt0=T[id*2].cnt0+T[id*2+1].cnt0;
T[id].cnt1=T[id*2].cnt1+T[id*2+1].cnt1;
T[id].lazy=0;
}
void down (int id) {
if (T[id].lazy%2==0) return;
swap(T[id*2].cnt0,T[id*2].cnt1);
T[id*2].lazy=T[id*2].lazy+T[id].lazy;
//
swap(T[id*2+1].cnt0,T[id*2+1].cnt1);
T[id*2+1].lazy=T[id*2+1].lazy+T[id].lazy;
//
T[id].lazy=0;
}
void update (int id,int l,int r,int c,int d,int x) {
if (r<c || l>d) return;
if (c<=l && r<=d) {
swap(T[id].cnt0,T[id].cnt1);
T[id].lazy=T[id].lazy+x;
return;
}
down(id);
int mid=(l+r)/2;
update(id*2,l,mid,c,d,x);
update(id*2+1,mid+1,r,c,d,x);
T[id].cnt0=T[id*2].cnt0+T[id*2+1].cnt0;
T[id].cnt1=T[id*2].cnt1+T[id*2+1].cnt1;
}
void incroad (int u,int v,int x) {
if (depth[u]>depth[v]) swap(u,v);
while (depth[v]>depth[u]) {
update(1,1,n,pos[head[v]],pos[v],x);
v=head[v];
v=dad[v];
}
while (head[u]!=head[v]) {
update(1,1,n,pos[head[u]],pos[u],x);
u=head[u];
u=dad[u];
update(1,1,n,pos[head[v]],pos[v],x);
v=head[v];
v=dad[v];
}
if (pos[u]<pos[v]) update(1,1,n,pos[u],pos[v],x);
else update(1,1,n,pos[v],pos[u],x);
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin>>n>>q;
FOR(i,1,n-1) {
int u,v;
cin>>u>>v;
adj[u].pb(v);
adj[v].pb(u);
}
int root;
FOR(i,1,n)
if (adj[i].size()>1) root=i;
//cout<<root<<'\n';
dfs(root,root);
head[root]=root;
HLD(root);
Build(1,1,n);
while (q--) {
int d;
cin>>d;
vector < int > a;
int e=n-1;
FOR(i,1,d) {
int x;
cin>>x;
a.pb(x);
if (numchild[x]==1) --leaf;
++numchild[x];
++leaf;
++e;
}
if (leaf&1) cout<<-1<<'\n';
else {
FOR(i,0,d-1) incroad(a[i],root,1);
e+=T[1].cnt0-1;
cout<<e<<'\n';
FOR(i,0,d-1) incroad(a[i],root,-1);
}
FOR(i,0,d-1) {
--numchild[a[i]];
if (numchild[a[i]]==1) ++leaf;
--leaf;
}
}
return 0;
}
Compilation message
cleaning.cpp: In function 'void dfs(int, int)':
cleaning.cpp:2:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
2 | #define FOR(i,a,b) for (int i=(a);i<=(b);i++)
| ^
cleaning.cpp:23:5: note: in expansion of macro 'FOR'
23 | FOR(i,0,adj[u].size()-1) {
| ^~~
cleaning.cpp: In function 'int main()':
cleaning.cpp:150:33: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized]
150 | FOR(i,0,d-1) incroad(a[i],root,-1);
| ~~~~~~~^~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
6488 KB |
Output is correct |
2 |
Incorrect |
187 ms |
8248 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
50 ms |
7644 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
37 ms |
8156 KB |
Output is correct |
2 |
Correct |
8 ms |
8156 KB |
Output is correct |
3 |
Correct |
33 ms |
22108 KB |
Output is correct |
4 |
Correct |
83 ms |
22124 KB |
Output is correct |
5 |
Correct |
28 ms |
20828 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
93 ms |
8800 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
184 ms |
11104 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
171 ms |
15656 KB |
Output is correct |
2 |
Incorrect |
96 ms |
18516 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
6488 KB |
Output is correct |
2 |
Incorrect |
187 ms |
8248 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |