hihocoder 1055 刷油漆(树形DP+背包)

dp[i][j]表示i节点，已经染色j个节点的最大价值，那就是树形DP，每个节点做一次背包

代码：

#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
using namespace std;

const int N = 105;

int n, m, val
, dp

;
vector<int> g
;

void dfs(int u, int p) {
memset(dp[u], 0, sizeof(dp[u]));
dp[u][1] = val[u];
for (int i = 0; i < g[u].size(); i++) {
int v = g[u][i];
if (v == p) continue;
dfs(v, u);
for (int j = m; j >= 2; j--) {
for (int k = 1; k < j; k++) {
dp[u][j] = max(dp[u][j], dp[u][j - k] + dp[v][k]);
}
}
}
}

int main() {
while (~scanf("%d%d", &n, &m)) {
for (int i = 1; i <= n; i++) {
scanf("%d", &val[i]);
g[i].clear();
}
int u, v;
for (int i = 0; i < n - 1; i++) {
scanf("%d%d", &u, &v);
g[u].push_back(v);
g[v].push_back(u);
}
dfs(1, 0);
printf("%d\n", dp[1][m]);
}
return 0;
}