1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
| #include <bits/stdc++.h>
using namespace std;
const int N = 6001;
int u, v, r[N], h[N], e[N], ne[N], idx, d[N];
int n, root, f[N][2];
void add(int u, int v) {
e[++idx] = v, ne[idx] = h[u], h[u] = idx;
}
void dfs(int u) {
f[u][0] = 0;
f[u][1] = r[u];
for (int i = h[u]; i; i = ne[i]) {
int v = e[i];
dfs(v);
f[u][0] += max(f[v][0], f[v][1]);
f[u][1] += f[v][0];
}
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; ++i) scanf("%d", &r[i]);
for (int i = 1; i < n; ++i) {
scanf("%d%d", &v, &u);
add(u, v);
++d[v];
}
for (int i = 1; i <= n; ++i)
if (!d[i]) {
root = i;
break;
}
dfs(root);
printf("%d\n", max(f[root][0], f[root][1]));
return 0;
}
|