| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 1327766 | aaaaaaaa | Mergers (JOI19_mergers) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mxN = 3005;
int dp[mxN][mxN], s[mxN], f[mxN], bad[mxN], exta = 0, cost = 0, ans = 1e18, st, n, k;
vector<int> adj[mxN];
void dfs(int u = 1, int par = 0){
dp[u][s[u]] = 1, bad[u] = 0;
for(auto it : adj[u]){
if(it ^ par){
dfs(it, u);
bad[u] |= bad[it];
for(int j = 1; j <= k; ++j){
dp[u][j] += dp[it][j];
}
}
}
bool ok = 1;
for(int j = 1; j <= k; ++j){
if(dp[u][j] != 0 && dp[u][j] != f[j]){
ok = 0;
}
}
if(ok && u != st) {
if(!bad[u]){
cost += 1;
bad[u] = 1;
}else{
exta = 1;
}
}
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
cin >> n >> k;
for(int i = 1, u, v; i <= n - 1; ++i){
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
for(int i = 1; i <= n; ++i){
cin >> s[i];
f[s[i]] += 1;
}
for(int i = 1; i <= 1; ++i){
st = i, cost = 0, exta = 0;
for(int j = 0; j <= n + 5; ++j){
for(int x = 0; x <= k + 5; ++x){
dp[j][x] = 0;
}
bad[j] = 0;
}
dfs(i, -1);
ans = min(ans, (cost + exta + 1) / 2);
//cout << i << " " << cost - 1 << "\n";
/cout << cost << " " << exta << " " << (cost + exta + 1) / 2 << "\n";
}
cout << ans << "\n";
return 0;
}