#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
const int mx = 100'000;
const int lg = 17;
using vi = vector<int>;
using vvi = vector<vi>;
#define sz(x) int(x.size())
vi edge[1+mx];
vvi anc(1+mx, vi(1+lg, 0));
vi order(1, 0);
vi order_index(1+mx, 0);
vi depth(1+mx, 0);
vi leaf(1+mx, 0);
vi st_leaf(1+mx, 0);
void dfs(int u)
{
order_index[u] = sz(order);
order.push_back(u);
st_leaf[u] = leaf[u];
for(int v: edge[u])
{
if(anc[u][0] == v) continue;
depth[v] = 1 + depth[u];
anc[v][0] = u;
dfs(v);
st_leaf[u] += st_leaf[v];
}
}
int ancestor(int u, int k)
{
for(int e = 0; e <= lg; e++)
if(k & (1<<e))
u = anc[u][e];
return u;
}
int lca(int u, int v)
{
if(depth[v] < depth[u]) swap(u, v);
v = ancestor(v, depth[v] - depth[u]);
if(u == v) return u;
for(int e = lg; e >= 0; e--)
{
if(anc[u][e] == anc[v][e]) continue;
u = anc[u][e];
v = anc[v][e];
}
return anc[u][0];
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int N, Q;
cin >> N >> Q;
for(int e = 1; e <= N-1; e++)
{
int u, v;
cin >> u >> v;
edge[u].push_back(v);
edge[v].push_back(u);
}
for(int i = 1; i <= N; i++)
if(sz(edge[i]) == 1)
leaf[i] = 1;
int rt = 1;
while(leaf[rt]) rt++;
dfs(rt);
for(int e = 1; e <= lg; e++)
for(int i = 1; i <= N; i++)
anc[i][e] = anc[ anc[i][e-1] ][e-1];
int leafcount = st_leaf[rt];
vi anc_even(1+N, 0);
for(int u: order)
{
if(u == 0) continue;
anc_even[u] = anc_even[ anc[u][0] ] + (st_leaf[u] % 2 == 0);
}
vi delta(1+N, 0);
vi exists(1+N, 0);
vi new_parent(1+N);
int basicAns = 0;
for(int i = 1; i <= N; i++)
{
if(i == rt) continue;
if(st_leaf[i] % 2 == 0) basicAns += 2;
else basicAns += 1;
}
for(int q = 1; q <= Q; q++)
{
int D;
cin >> D;
int new_leafcount = leafcount;
vi a(D);
for(int d = 0; d < D; d++)
{
cin >> a[d];
if(leaf[a[d]])
{
leaf[a[d]] = 0;
new_leafcount--;
delta[a[d]] ^= 1;
}
new_leafcount++;
delta[a[d]] ^= 1;
}
// cerr << "read input\n";
if(new_leafcount % 2 == 1)
{
cout << "-1\n";
for(int z: a)
{
delta[z] = 0;
leaf[z] = (sz(edge[z]) == 1);
}
continue;
}
int ans = D + basicAns;
sort(a.begin(), a.end(), [] (int u, int v)
{
return order_index[u] < order_index[v];
});
for(int i = 0; i < D-1; i++)
a.push_back(lca(a[i], a[i+1]));
a.push_back(rt);
vi a_unique;
// cerr << "A\n";
for(int z: a)
{
if(exists[z]) continue;
exists[z] = 1;
a_unique.push_back(z);
}
for(int z: a) exists[z] = 0;
sort(a_unique.begin(), a_unique.end(), [] (int u, int v)
{
return order_index[u] < order_index[v];
});
// cerr << "B\n";
vi st{a_unique[0]};
int aux_root = st[0];
new_parent[aux_root] = 0;
for(int y = 1; y < sz(a_unique); y++)
{
int u = a_unique[y];
while(depth[u] <= depth[st.back()] || ancestor(u, depth[u] - depth[st.back()]) != st.back())
st.pop_back();
new_parent[u] = st.back();
st.push_back(u);
}
// cerr << "C\n";
sort(a_unique.begin(), a_unique.end(), [] (int u, int v)
{
return depth[u] > depth[v];
});
for(int y = 0; y < sz(a_unique)-1; y++)
{
int u = a_unique[y];
if(delta[u])
ans += (depth[u] - depth[new_parent[u]]) - (anc_even[u] - anc_even[new_parent[u]]);
delta[ new_parent[u] ] ^= delta[u];
}
// cerr << "D\n";
for(int z: a)
{
delta[z] = 0;
leaf[z] = (sz(edge[z]) == 1);
}
cout << ans << '\n';
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
10 ms |
14376 KB |
Output is correct |
2 |
Incorrect |
60 ms |
16192 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
24 ms |
15568 KB |
Output is correct |
2 |
Correct |
15 ms |
15224 KB |
Output is correct |
3 |
Correct |
64 ms |
20544 KB |
Output is correct |
4 |
Correct |
80 ms |
20064 KB |
Output is correct |
5 |
Correct |
100 ms |
21624 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
26 ms |
16104 KB |
Output is correct |
2 |
Correct |
23 ms |
15688 KB |
Output is correct |
3 |
Correct |
61 ms |
26300 KB |
Output is correct |
4 |
Correct |
84 ms |
26888 KB |
Output is correct |
5 |
Correct |
58 ms |
25404 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
46 ms |
16796 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
75 ms |
19276 KB |
Output is correct |
2 |
Incorrect |
112 ms |
19268 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
128 ms |
21692 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
10 ms |
14376 KB |
Output is correct |
2 |
Incorrect |
60 ms |
16192 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |