| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 1289167 | ninhtay | Dostavljač (COCI18_dostavljac) | C11 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
using namespace std;
const long long NEG = -1e15;
int N, M;
long long A[505];
vector<int> g[505];
bool vis[505];
pair<vector<long long>, vector<long long>> dfs(int u) {
vis[u] = true;
vector<long long> f_ret(M + 1, NEG), f_open(M + 1, NEG);
f_ret[0] = f_open[0] = 0;
if (M >= 1) f_ret[1] = f_open[1] = A[u];
for (int v : g[u]) if (!vis[v]) {
auto [cr, co] = dfs(v);
vector<long long> new_ret = f_ret, new_open = f_open;
for (int t1 = 0; t1 <= M; t1++) {
if (f_ret[t1] <= NEG/2 && f_open[t1] <= NEG/2) continue;
for (int t2 = 0; t2 <= M; t2++) {
if (cr[t2] <= NEG/2) continue;
int cost = t1 + t2 + 2;
if (cost <= M) {
if (f_ret[t1] > NEG/2) new_ret[cost] = max(new_ret[cost], f_ret[t1] + cr[t2]);
if (f_open[t1] > NEG/2) new_open[cost] = max(new_open[cost], f_open[t1] + cr[t2]);
}
}
for (int t2 = 0; t2 <= M; t2++) {
if (co[t2] <= NEG/2) continue;
int cost = t1 + t2 + 1;
if (cost <= M && f_ret[t1] > NEG/2)
new_open[cost] = max(new_open[cost], f_ret[t1] + co[t2]);
}
}
f_ret.swap(new_ret);
f_open.swap(new_open);
}
return {f_ret, f_open};
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> N >> M;
for (int i = 1; i <= N; i++) cin >> A[i];
for (int i = 0; i < N - 1; i++) {
int u, v; cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
auto [fr, fo] = dfs(1);
long long ans = 0;
for (int t = 0; t <= M; t++) ans = max({ans, fr[t], fo[t]});
cout << ans;
}
