比赛 |
2025暑期集训第4场 |
评测结果 |
AWWWWWWWWW |
题目名称 |
外卖 |
最终得分 |
10 |
用户昵称 |
OTTF |
运行时间 |
0.362 s |
代码语言 |
C++ |
内存使用 |
5.86 MiB |
提交时间 |
2025-07-05 11:37:03 |
显示代码纯文本
#include <algorithm>
#include <cstdio>
#include <iostream>
#include <vector>
using namespace std;
constexpr int N = 514;
int n;
int m;
long long nums[N];
vector<int> tree[N];
long long dp[N][N][2][2];
long long res;
inline long long get (int u, int t, bool one, bool two) {
return (t >= 0 ? dp[u][t][one][two] : 0);
}
void display () {
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
cout << dp[i][j][0][0] << ' ' << dp[i][j][1][0] << ' ' << dp[i][j][0][1] << ' ' << dp[i][j][1][1] << endl;
}
}
}
void dp1 (int now, int dad) {
if (now != 1 && tree[now].size() == 1) {
for (int i = 1; i <= m; i++) {
dp[now][i][1][1] = nums[now];
}
return;
}
int cc = 0;
for (auto son : tree[now]) {
if (son == dad) {
continue;
}
cc++;
dp1 (son, now);
int t;
long long temp;
for (int i = m; i >= 1; i--) {
t = i;
temp = max ({get (son, t - 1, 0, 0), get (son, t - 1, 0, 1), get (son, t - 1, 1, 0), get (son, t - 1, 1, 1)});
dp[now][i][0][0] = max (dp[now][i][0][0], temp);
temp = max ({get (son, t - 2, 0, 0), get (son, t - 2, 0, 1), get (son, t - 2, 1, 0), get (son, t - 2, 1, 1)});
dp[now][i][1][0] = max (dp[now][i][1][0], temp);
temp = max ({get (son, t - 2, 0, 1), get (son, t - 2, 1, 1)});
dp[now][i][0][1] = max (dp[now][i][0][1], temp);
temp = max ({get (son, t - 3, 0, 1), get (son, t - 3, 1, 1)});
dp[now][i][1][1] = max (dp[now][i][1][1], temp);
if (cc == 1) {
continue;
}
for (int j = i - 1; j > 0; j--) {
t = i - j;
temp = max ({get (son, t - 1, 0, 0), get (son, t - 1, 0, 1), get (son, t - 1, 1, 0), get (son, t - 1, 1, 1)});
dp[now][i][0][0] = max (dp[now][i][0][0], dp[now][j][0][1] + temp);
temp = max ({get (son, t - 1, 0, 0), get (son, t - 1, 0, 1), get (son, t - 1, 1, 0), get (son, t - 1, 1, 1)});
dp[now][i][1][0] = max (dp[now][i][1][0], dp[now][j][1][1] + temp);
temp = max ({get (son, t - 2, 0, 1), get (son, t - 2, 1, 1)});
dp[now][i][0][1] = max (dp[now][i][0][1], dp[now][j][0][1] + temp);
temp = max ({get (son, t - 2, 0, 1), get (son, t - 2, 1, 1)});
dp[now][i][1][1] = max (dp[now][i][1][1], dp[now][j][1][1] + temp);
}
}
}
for (int i = 1; i <= m; i++) {
dp[now][i][1][1] += nums[now];
dp[now][i][1][0] += nums[now];
}
}
int main () {
freopen ("food.in", "r", stdin);
freopen ("food.out", "w", stdout);
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> nums[i];
}
int u, v;
for (int i = 1; i < n; i++) {
cin >> u >> v;
tree[u].push_back(v);
tree[v].push_back(u);
}
dp1 (1, 0);
cout << max ({dp[1][m][0][0], dp[1][m][1][0], dp[1][m][0][1], dp[1][m][1][1]}) << endl;
return 0;
}