记录编号	602728	评测结果	AAAAAAAAAA
题目名称	4085.外卖	最终得分	100
用户昵称	LikableP	是否通过	通过
代码语言	C++	运行时间	0.338 s
提交时间	2025-07-05 15:58:18	内存使用	2.15 MiB

#include <cstdio>

template <typename T> T read();
template <typename T> void write(T, char);
template <typename T> T max(T, T);
void AddEdge(int, int);
void dfs(int, int);

const int MAXN = 510;

int n, k;
int a[MAXN];
int f[MAXN][MAXN][2];
#define GONE 0
#define BACK 1

int main() {
  freopen("food.in", "r", stdin);
  freopen("food.out", "w", stdout);
  n = read<int>(), k = read<int>();
  for (int i = 1; i <= n; ++i) {
    a[i] = read<int>();
  }
  for (int i = 1; i <= n - 1; ++i) {
    int u = read<int>(), v = read<int>();
    AddEdge(u, v);
    AddEdge(v, u);
  }

  dfs(1, 0);

  write(max(f[1][k][GONE], f[1][k][BACK]), '\n');
  return 0;
}

struct EDGE {
  int v, next;
} edge[MAXN << 1];

int head[MAXN], edgeNum;
void dfs(int now, int fa) {
  f[now][1][GONE] = f[now][1][BACK] = a[now];
  for (int i = head[now]; i; i = edge[i].next) {
    int v = edge[i].v;
    if (v == fa) continue;
    dfs(v, now);
    for (int t = k; t >= 1; --t)
      for (int j = 1; j <= t; ++j) {
        f[now][t][GONE] = max(f[now][t][GONE], f[now][t - j][BACK] + f[v][j - 1][GONE]);
        if (j >= 2) {
          f[now][t][GONE] = max(f[now][t][GONE], f[v][j - 2][BACK] + f[now][t - j][GONE]);
          f[now][t][BACK] = max(f[now][t][BACK], f[v][j - 2][BACK] + f[now][t - j][BACK]);
        }
      }
  }
}

void AddEdge(int u, int v) {
  edge[++edgeNum] = {v, head[u]};
  head[u] = edgeNum;
}

template <typename T> T max(T x, T y) {
  return x > y ? x : y;
}

#define isdigit(ch) ((ch) >= '0' && (ch) <= '9')
template <typename T> T read() {
  T res = 0, f = 1;
  char ch = getchar();
  for (; !isdigit(ch); ch = getchar())
    if (ch == '-') f = -1;
  for (; isdigit(ch); ch = getchar()) res = (res << 3) + (res << 1) + (ch ^ 48);
  return res * f;
}

template <typename T> void write(T x, char ed) {
  if (x < 0) x = -x, putchar('-');
  static int sta[sizeof(T) << 2], top = 0;
  do {
    sta[++top] = x % 10;
    x /= 10;
  } while (x);
  while (top) {
    putchar(sta[top--] ^ 48);
  }
  putchar(ed);
}