#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) (x).begin(), (x).end()
const int N = 5e5 + 7, L = 20;
int n, k;
vector<int> adj[N];
int c[N], dep[N];
int lift[N][L];
int l[N], cum[N];
int cnt, r;
bool seen[N];
void prep(int v = 1, int p = 0) {
lift[v][0] = p;
for (int i = 1; i < L; i++)
lift[v][i] = lift[lift[v][i - 1]][i - 1];
for (int u : adj[v]) {
if (u == p)
continue;
dep[u] = dep[v] + 1;
prep(u, v);
}
}
int lca(int u, int v) {
if (u == 0 || v == 0)
return max(u, v);
if (dep[u] > dep[v])
swap(u, v);
for (int i = 0; i < L; i++)
if ((dep[v] - dep[u]) >> i & 1)
v = lift[v][i];
if (u == v)
return u;
for (int i = L - 1; i >= 0; i--)
if (lift[v][i] != lift[u][i])
v = lift[v][i], u = lift[u][i];
return lift[u][0];
}
void run(int v = 1, int p = 0) {
for (int u : adj[v]) {
if (u == p)
continue;
run(u, v);
cum[v] += cum[u];
}
}
void dfs(int v = 1, int p = 0) {
for (int u : adj[v]) {
if (u == p)
continue;
dfs(u, v);
seen[v] |= seen[u];
}
if (v != 1 && !cum[v] && !seen[v]) {
cnt++;
r = lca(r, v);
seen[v] = 1;
}
}
int main() {
cin.tie(0)->sync_with_stdio(false);
cin >> n >> k;
for (int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
prep();
for (int i = 1; i <= n; i++) {
cin >> c[i];
l[c[i]] = lca(l[c[i]], i);
}
for (int i = 1; i <= n; i++)
cum[i]++, cum[l[c[i]]]--;
run();
dfs();
if (!r) {
cout << 0 << '\n';
return 0;
}
int need = 0;
while (r != 1) {
if (!cum[r])
need = 1;
r = lift[r][0];
}
cout << cnt + need - 1 << '\n';
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
18264 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
18264 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
18264 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
31 ms |
29756 KB |
Output is correct |
2 |
Incorrect |
36 ms |
30548 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
18264 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |