#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int N = 1e5 + 50;
int n, q, h[N], par[20][N], st[N], ft[N], t, cnt[N], sub[N];
int oa, ans, lf[N];
int p[N];
bool mark[N];
vector<int> adj[N], adj2[N];
vector<int> vc;
void dfs(int u, int p) {
st[u] = ++t;
par[0][u] = p;
h[u] = h[p]+1;
for (int v:adj[u]) {
if (v==p) continue;
dfs(v, u);
sub[u] += sub[v];
}
ft[u] = t;
}
void dfs2(int u, int p) {
for (int v:adj[u]) {
if (v == p) continue;
cnt[v] = cnt[u] + 1-(sub[v]&1);
oa += 1-(sub[v]&1);
dfs2(v, u);
}
}
int Par(int u, int x) {
for (int k = 0; k < 20; k++) {
if (x>>k&1) u = par[k][u];
}
return u;
}
int LCA(int u, int v) {
if (h[u] < h[v]) swap(u, v);
u = Par(u, h[u]-h[v]);
for (int k = 19; k >= 0; k--) {
if (par[k][u] != par[k][v]) {
u = par[k][u];
v = par[k][v];
}
}
if (u == v) return u;
return par[0][u];
}
int f(int u, int v) {
return (h[v]-h[u])-2*(cnt[v]-cnt[u]);
}
void sfd(int u, int p) {
for (int v:adj2[u]) {
if (v == p) continue;
sfd(v, u);
lf[u] += lf[v];
if (lf[v]&1) ans += f(u, v);
}
}
bool cmp(int u, int v) {
return st[u] < st[v];
}
void solve() {
cin >> n >> q;
for (int i = 1; i <= n-1; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
int r = 0;
for (int u = 1; u <= n; u++) {
if(adj[u].size() > 1) {
if (!r) r = u;
}
else {
mark[u] = 1;
sub[u] = 1;
}
}
dfs(r, 0);
dfs2(r, 0);
for (int k = 1; k < 20; k++) {
for (int u = 1; u <= n; u++) {
par[k][u] = par[k-1][par[k-1][u]];
}
}
for (int u = 1; u <= n; u++) {
lf[u] = mark[u];
}
ans = oa;
while (q--) {
int d;
cin >> d;
for (int i = 1; i <= d; i++) {
int u;
cin >> u;
lf[u]++;
vc.push_back(u);
}
vc.push_back(1);
sort(vc.begin(), vc.end(), cmp);
vc.resize(unique(vc.begin(), vc.end()) - vc.begin());
int tmp = vc.size();
for (int i = 1; i < tmp; i++) {
int u = vc[i];
int v = vc[i-1];
vc.push_back(LCA(u, v));
}
sort(vc.begin(), vc.end(), cmp);
vc.resize(unique(vc.begin(), vc.end()) - vc.begin());
for (int i = 1; i < (int)vc.size(); i++) {
int u = vc[i];
p[u] = vc[i-1];
while (st[u] > ft[p[u]]) p[u] = p[p[u]];
adj2[u].push_back(p[u]);
adj2[p[u]].push_back(u);
}
sfd(vc[0], 0);
cout << ((sub[r] + lf[vc[0]])&1 ? -1:n+d-1+ans) << endl;
for (int v:vc) {
lf[v] = mark[v];
adj2[v].clear();
}
vc.clear();
ans = oa;
}
}
int main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
solve();
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
5076 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
6284 KB |
Output is correct |
2 |
Correct |
16 ms |
6100 KB |
Output is correct |
3 |
Correct |
42 ms |
19396 KB |
Output is correct |
4 |
Correct |
80 ms |
17240 KB |
Output is correct |
5 |
Correct |
112 ms |
21660 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
18 ms |
6756 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
41 ms |
9208 KB |
Output is correct |
2 |
Correct |
32 ms |
8420 KB |
Output is correct |
3 |
Correct |
11 ms |
7892 KB |
Output is correct |
4 |
Incorrect |
11 ms |
8532 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
57 ms |
16428 KB |
Output is correct |
2 |
Correct |
199 ms |
15752 KB |
Output is correct |
3 |
Correct |
83 ms |
10572 KB |
Output is correct |
4 |
Correct |
173 ms |
15756 KB |
Output is correct |
5 |
Correct |
145 ms |
15848 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
113 ms |
22496 KB |
Output is correct |
2 |
Correct |
107 ms |
27072 KB |
Output is correct |
3 |
Incorrect |
176 ms |
26928 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
5076 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |