#include <bits/stdc++.h>
constexpr int N = 2e5;
std::vector<int> e[N], edges[N], rev[N];
int c[N], up[N][20], in[N], out[N], timeStamp, lc[N], mx[N][20], mn[N][20];
void dfs(int u, int p) {
in[u] = timeStamp++;
up[u][0] = p;
mx[u][0] = mn[u][0] = c[u];
for (int i = 1; i < 20; i++) {
up[u][i] = up[up[u][i - 1]][i - 1];
mn[u][i] = std::min(mn[u][i - 1], mn[up[u][i - 1]][i - 1]);
mx[u][i] = std::max(mx[u][i - 1], mx[up[u][i - 1]][i - 1]);
}
for (auto v : e[u]) {
if (v != p) {
dfs(v, u);
}
}
out[u] = timeStamp;
}
inline bool is(int u, int v) {
return in[u] <= in[v] && out[u] >= out[v];
}
int lca(int u, int v) {
if (is(u, v)) return u;
if (is(v, u)) return v;
for (int i = 19; i >= 0; i--) {
if (!is(up[u][i], v)) {
u = up[u][i];
}
}
return up[u][0];
}
std::vector<bool> vis;
std::vector<int> order, comp[N];
std::set<int> ne[N];
void dfs2(int u) {
vis[u] = true;
for (auto v : edges[u]) {
if (!vis[v]) {
dfs2(v);
}
}
order.push_back(u);
}
int belong[N], timer = 0, siz[N];
void dfs3(int u) {
comp[timer].push_back(u);
belong[u] = timer;
siz[timer]++;
vis[u] = true;
for (auto v : rev[u]) {
if (!vis[v]) {
dfs3(v);
}
}
}
int dp[N];
int calc(int u) {
if (~dp[u]) {
return dp[u];
}
dp[u] = siz[u];
for (auto v : ne[u]) {
dp[u] += calc(v);
}
return dp[u];
}
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int n, k;
std::cin >> n >> k;
for (int i = 0; i < n - 1; i++) {
int u, v;
std::cin >> u >> v;
u--;
v--;
e[u].push_back(v);
e[v].push_back(u);
}
std::vector<int> comlca(k);
for (int i = 0; i < n; i++) {
std::cin >> c[i];
c[i]--;
comlca[c[i]] = i;
}
dfs(0, 0);
for (int i = 0; i < n; i++) {
comlca[c[i]] = lca(comlca[c[i]], i);
}
for (int i = 1; i < n; i++) {
int u = i;
for (int j = 18; j >= 0; j--) {
if (mx[u][j + 1] == mn[u][j + 1] && (!is(up[u][j], comlca[c[i]]))) {
u = up[u][j];
}
}
u = up[u][0];
if (c[u] != c[i]) {
// std::cout << c[i] + 1 << " " << c[u] + 1 << "\n";
edges[c[i]].push_back(c[u]);
rev[c[u]].push_back(c[i]);
}
}
vis.assign(k, 0);
for (int i = 0; i < k; i++) {
if (!vis[i]) {
dfs2(i);
}
}
memset(belong, -1, sizeof belong);
vis.assign(k, 0);
reverse(order.begin(), order.end());
for (auto u : order) {
if (vis[u]) {
continue;
}
dfs3(u);
// for (auto x : comp[timer]) {
// std::cout << x + 1 << " ";
// }std::cout << "\n\n";
timer++;
}
for (int i = 0; i < k; i++) {
for (auto v : edges[i]) {
if (belong[i] != belong[v]) {
ne[belong[i]].insert(belong[v]);
// std::cout << belong[i] << " " << belong[v] << "\n";
}
}
}
memset(dp, -1, sizeof dp);
int ans = 1e9;
for (int i = 0; i < timer; i++) {
ans = std::min(ans, calc(i));
}
std::cout << ans - 1 << "\n";
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
30056 KB |
Output is correct |
2 |
Correct |
18 ms |
30068 KB |
Output is correct |
3 |
Correct |
17 ms |
30072 KB |
Output is correct |
4 |
Incorrect |
20 ms |
30056 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
30056 KB |
Output is correct |
2 |
Correct |
18 ms |
30068 KB |
Output is correct |
3 |
Correct |
17 ms |
30072 KB |
Output is correct |
4 |
Incorrect |
20 ms |
30056 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
585 ms |
105588 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
18 ms |
30056 KB |
Output is correct |
2 |
Correct |
18 ms |
30068 KB |
Output is correct |
3 |
Correct |
17 ms |
30072 KB |
Output is correct |
4 |
Incorrect |
20 ms |
30056 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |