Files
OI-source/1.1122.cpp
2023-08-03 09:22:52 +08:00

38 lines
643 B
C++

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
using namespace std;
const int maxn=16005;
int n,a[maxn],f[maxn];
vector<int> G[maxn];
void dfs(int u,int fa)
{
f[u]=a[u];
for(int i=0;i<G[u].size();i++)
{
int v=G[u][i];
if(v==fa) continue;
dfs(v,u);
if(f[v]>0) f[u]+=f[v];
}
}
int main()
{
#ifdef local
freopen("pro.in","r",stdin);
#endif
scanf("%d",&n);
for(int i=1;i<=n;i++) scanf("%d",&a[i]);
for(int i=1;i<=n-1;i++)
{
int u,v; scanf("%d%d",&u,&v);
G[v].push_back(u);
G[u].push_back(v);
}
dfs(1,-1);
int res=f[1];
for(int i=2;i<=n;i++) res=max(res,f[i]);
printf("%d\n",res);
return 0;
}