#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];
});
// cerr << "au = ";
// for(int au: a_unique) cerr << au << " " << delta[au] << '\n';
for(int y = 0; y < sz(a_unique)-1; y++)
{
int u = a_unique[y];
if(delta[u])
{
// cerr << "inverting path " << u << " to " << new_parent[u] << " with " <<
ans += (depth[u] - depth[new_parent[u]]) - 2*(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';
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
14352 KB |
Output is correct |
2 |
Correct |
82 ms |
15580 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
32 ms |
15248 KB |
Output is correct |
2 |
Correct |
16 ms |
14852 KB |
Output is correct |
3 |
Correct |
59 ms |
19984 KB |
Output is correct |
4 |
Correct |
88 ms |
19420 KB |
Output is correct |
5 |
Correct |
102 ms |
21084 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
25 ms |
15680 KB |
Output is correct |
2 |
Correct |
18 ms |
15444 KB |
Output is correct |
3 |
Correct |
71 ms |
25792 KB |
Output is correct |
4 |
Correct |
86 ms |
26024 KB |
Output is correct |
5 |
Correct |
74 ms |
24628 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
44 ms |
16020 KB |
Output is correct |
2 |
Correct |
32 ms |
15836 KB |
Output is correct |
3 |
Correct |
20 ms |
15676 KB |
Output is correct |
4 |
Correct |
20 ms |
16068 KB |
Output is correct |
5 |
Correct |
23 ms |
16208 KB |
Output is correct |
6 |
Correct |
44 ms |
16368 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
76 ms |
18100 KB |
Output is correct |
2 |
Correct |
114 ms |
17792 KB |
Output is correct |
3 |
Correct |
79 ms |
17096 KB |
Output is correct |
4 |
Correct |
132 ms |
19260 KB |
Output is correct |
5 |
Correct |
126 ms |
19140 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
137 ms |
20192 KB |
Output is correct |
2 |
Correct |
143 ms |
24404 KB |
Output is correct |
3 |
Correct |
147 ms |
24276 KB |
Output is correct |
4 |
Correct |
140 ms |
23992 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
14352 KB |
Output is correct |
2 |
Correct |
82 ms |
15580 KB |
Output is correct |
3 |
Correct |
32 ms |
15248 KB |
Output is correct |
4 |
Correct |
16 ms |
14852 KB |
Output is correct |
5 |
Correct |
59 ms |
19984 KB |
Output is correct |
6 |
Correct |
88 ms |
19420 KB |
Output is correct |
7 |
Correct |
102 ms |
21084 KB |
Output is correct |
8 |
Correct |
25 ms |
15680 KB |
Output is correct |
9 |
Correct |
18 ms |
15444 KB |
Output is correct |
10 |
Correct |
71 ms |
25792 KB |
Output is correct |
11 |
Correct |
86 ms |
26024 KB |
Output is correct |
12 |
Correct |
74 ms |
24628 KB |
Output is correct |
13 |
Correct |
44 ms |
16020 KB |
Output is correct |
14 |
Correct |
32 ms |
15836 KB |
Output is correct |
15 |
Correct |
20 ms |
15676 KB |
Output is correct |
16 |
Correct |
20 ms |
16068 KB |
Output is correct |
17 |
Correct |
23 ms |
16208 KB |
Output is correct |
18 |
Correct |
44 ms |
16368 KB |
Output is correct |
19 |
Correct |
76 ms |
18100 KB |
Output is correct |
20 |
Correct |
114 ms |
17792 KB |
Output is correct |
21 |
Correct |
79 ms |
17096 KB |
Output is correct |
22 |
Correct |
132 ms |
19260 KB |
Output is correct |
23 |
Correct |
126 ms |
19140 KB |
Output is correct |
24 |
Correct |
137 ms |
20192 KB |
Output is correct |
25 |
Correct |
143 ms |
24404 KB |
Output is correct |
26 |
Correct |
147 ms |
24276 KB |
Output is correct |
27 |
Correct |
140 ms |
23992 KB |
Output is correct |
28 |
Correct |
111 ms |
18948 KB |
Output is correct |
29 |
Correct |
143 ms |
23920 KB |
Output is correct |
30 |
Correct |
63 ms |
21572 KB |
Output is correct |
31 |
Correct |
86 ms |
27572 KB |
Output is correct |
32 |
Correct |
126 ms |
19140 KB |
Output is correct |
33 |
Correct |
156 ms |
22172 KB |
Output is correct |
34 |
Correct |
207 ms |
23972 KB |
Output is correct |
35 |
Correct |
225 ms |
23876 KB |
Output is correct |