#include <bits/stdc++.h>
using namespace std;
#define sz(x) ((int)size(x))
#define all(x) begin(x), end(x)
#define trace(x) cout << #x << ": " << (x) << endl;
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) { return (int) ((ll) rnd() % (r - l + 1)) + l; }
const int N = 200000, infI = 1e9 + 7;
const ll infL = 3e18;
vector<int> g[N];
ll dp[N];//LL???
int cnt[N], parent[N], depth[N], cnt1[N], cnt2[N];
void pull(int v) {
dp[v] = 0;
if (sz(g[v]) <= 1) {
//v is a leaf
cnt[v] = 1;
} else {
cnt[v] = 0;
for (int to: g[v]) {
if (to != parent[v]) {
cnt[v] += cnt[to];
dp[v] += dp[to];
}
}
}
dp[v] += 2 - (cnt[v] & 1);
}
void dfs(int v, int p) {
if (p != -1) {
depth[v] = depth[p] + 1;
}
dp[v] = 0;
parent[v] = p;
if (sz(g[v]) <= 1) {
//v is a leaf
cnt[v] = 1;
} else {
cnt[v] = 0;
for (int to: g[v]) {
if (to != parent[v]) {
dfs(to, v);
cnt[v] += cnt[to];
dp[v] += dp[to];
}
}
}
dp[v] += 2 - (cnt[v] & 1);
}
void gfs(int v) {
if (parent[v] != -1) {
cnt1[v] = cnt1[parent[v]];
cnt2[v] = cnt2[parent[v]];
}
if (cnt[v] & 1) {
++cnt1[v];
} else {
++cnt2[v];
}
for (int to: g[v]) {
if (to != parent[v]) {
gfs(to);
}
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n, q;
cin >> n >> q;
int root = -1;
for (int i = 0; i < n - 1; ++i) {
int a, b;
cin >> a >> b;
--a, --b;
g[a].push_back(b);
g[b].push_back(a);
}
int mxx = 0;
for (int i = 0; i < n; ++i) {
mxx = max(mxx, sz(g[i]));
}
for (int i = 0; i < n; ++i) {
if (sz(g[i]) > 1) {
root = i;
break;
}
}
assert(root != -1);
dfs(root, -1);
gfs(root);
while (q--) {
int D;
cin >> D;
vector<int> a(D);
for (int i = 0; i < D; ++i) {
cin >> a[i];
--a[i];
}
if (D == 1) {
if (sz(g[a[0]]) == 1) {
cout << ((cnt[root] % 2 == 1 ? -1 : dp[root] - 1)) << '\n';
} else {
cout << (cnt[root] % 2 == 0 ? -1 : dp[root] - cnt2[a[0]] * 2 - cnt1[a[0]] * 1 + cnt2[a[0]] * 1 +
cnt1[a[0]] * 2 - 1) << '\n';
}
} else {
exit(1);
}
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
3 ms |
4948 KB |
Execution failed because the return code was nonzero |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
9 ms |
5724 KB |
Execution failed because the return code was nonzero |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
10 ms |
6304 KB |
Execution failed because the return code was nonzero |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
10 ms |
6996 KB |
Execution failed because the return code was nonzero |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
44 ms |
9316 KB |
Output is correct |
2 |
Runtime error |
39 ms |
9024 KB |
Execution failed because the return code was nonzero |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
111 ms |
12076 KB |
Output is correct |
2 |
Correct |
88 ms |
16116 KB |
Output is correct |
3 |
Correct |
97 ms |
16216 KB |
Output is correct |
4 |
Correct |
82 ms |
15572 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
3 ms |
4948 KB |
Execution failed because the return code was nonzero |
2 |
Halted |
0 ms |
0 KB |
- |