#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 10, LG = 20;
int p[N], sz[N], dep[N], st[N][LG], conn[N], tin[N], timer = 0, cc = 0, leaf = 0;
vector<int> adj[N], sta[N];
int find(int u) {
return p[u] == u ? u : p[u] = find(p[u]);
}
void merge(int u, int v) {
u = find(u), v = find(v);
if (u == v) return;
p[v] = u;
}
void dfs(int u, int p) {
tin[u] = ++timer;
for (int i = 1; i < LG; i++) {
st[u][i] = st[st[u][i - 1]][i - 1];
}
for (int v : adj[u]) {
if (v == p) continue;
st[v][0] = u;
dep[v] = dep[u] + 1;
dfs(v, u);
}
}
int getLCA(int u, int v) {
if (dep[u] < dep[v]) swap(u, v);
for (int i = LG - 1; i >= 0; i--) {
if ((dep[u] - dep[v]) & (1 << i)) {
u = st[u][i];
}
}
if (u == v) return u;
for (int i = LG - 1; i >= 0; i--) {
int ut = st[u][i], vt = st[v][i];
if (ut != vt) u = ut, v = vt;
}
return st[u][0];
}
int32_t main() {
ios::sync_with_stdio(0); cin.tie(0);
int n, k;
cin >> n >> k;
if (n == 1) {
cout << "0\n";
return 0;
}
for (int i = 1; i <= n; i++) p[i] = i, sz[i] = 1;
for (int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int i = 1; i <= n; i++) {
if ((int) adj[i].size() == 1) leaf++;
}
st[1][0] = 1;
dfs(1, -1);
for (int i = 1; i <= n; i++) {
int x;
cin >> x;
sta[x].push_back(i);
}
for (int i = 1; i <= k; i++) {
sort(sta[i].begin(), sta[i].end(), [&] (int x, int y) {
return tin[x] < tin[y];
});
for (int j = 1; j < (int) sta[i].size(); j++) {
int x = sta[i][j - 1], y = sta[i][j];
int lca = getLCA(x, y);
while (dep[x] > dep[lca]) {
merge(st[x][0], x);
x = find(x);
}
while (dep[y] > dep[lca]) {
merge(st[y][0], y);
y = find(y);
}
}
}
for (int i = 1; i <= n; i++) conn[find(i)] = 1;
for (int i = 1; i <= n; i++) if (conn[i]) cc++;
int ans = 2;
ans = min(ans, leaf - 1);
if (cc == 1) ans = min(ans, 0);
else if (k < n) ans = min(ans, 1);
else ans = min(ans, 2);
cout << ans << '\n';
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
23896 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
23896 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
23896 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
60 ms |
38860 KB |
Output is correct |
2 |
Incorrect |
63 ms |
41912 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
11 ms |
23896 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |