比赛 |
2025暑期集训第4场 |
评测结果 |
WWWWWWWWWW |
题目名称 |
外卖 |
最终得分 |
0 |
用户昵称 |
LikableP |
运行时间 |
0.284 s |
代码语言 |
C++ |
内存使用 |
2.15 MiB |
提交时间 |
2025-07-05 10:34:07 |
显示代码纯文本
#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, m;
int a[MAXN];
int f[MAXN][MAXN][2];
int main() {
freopen("food.in", "r", stdin);
freopen("food.out", "w", stdout);
n = read<int>(), m = 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][m][0], f[1][m][1]), '\n');
// for (int i = 0; i <= 1; ++i) {
// for (int j = 1; j <= n; ++j) {
// for (int k = 1; k <= m; ++k) {
// fprintf(stderr, "f[%d][%d][%d]=%d%c", j, k, i, f[j][k][i], " \n"[k == m]);
// }
// }
// fprintf(stderr, "\n");
// }
return 0;
}
struct EDGE {
int v, next;
} edge[MAXN << 1];
int head[MAXN], edgeNum;
void dfs(int now, int fa) {
// fprintf(stderr, "[Enter now=%d fa=%d]\n", now, fa);
f[now][1][1] = f[now][0][1] = 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 j = m; j >= 0; --j) {
for (int t = 0; j - t - 2 >= 0; ++t) {
// fprintf(stderr, "f[%d][%d][%d]=max(f[%d][%d][%d](%d),f[%d][%d][%d](%d)+f[%d][%d][%d](%d)\n", now, j, 1, now, j, 1, f[now][j][1], v, t, 1, f[v][t][1], now, j - t - 2, 1, f[now][j - t - 2][1]);
f[now][j][1] = max(f[now][j][1], f[v][t][1] + f[now][j - t - 2][1]);
// fprintf(stderr, "f[%d][%d][%d]=max(f[%d][%d][%d](%d),f[%d][%d][%d](%d)+f[%d][%d][%d](%d)\n", now, j, 0, now, j, 0, f[now][j][0], v, t, 1, f[v][t][1], now, j - t - 2, 1, f[now][j - t - 2][0]);
f[now][j][0] = max(f[now][j][0], f[v][t][1] + f[now][j - t - 2][0]);
// fprintf(stderr, "f[%d][%d][%d]=max(f[%d][%d][%d](%d),f[%d][%d][%d](%d)+f[%d][%d][%d](%d)\n\n", now, j, 0, now, j, 0, f[now][j][0], now, t, 1, f[now][t][1], v, j - t - 2, 0, f[v][j - t - 2][0]);
f[now][j][0] = max(f[now][j][0], f[now][t][1] + f[v][j - t - 2][0]);
}
}
}
// fprintf(stderr, "[Exitt now=%d fa=%d]\n", now, fa);
}
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);
}