两个错误
by gmx0424 @ 2023-10-23 17:06:48
```cpp
#include<bits/stdc++.h>
using namespace std;
int n,a[6001],tot,f[6001][2],ans,root,vis[6001],head[6001];
bool is_h[6001];
struct edge
{
int to,next;
}e[6001];
void addedge(int u,int v)
{
++tot;
e[tot].to=v;
e[tot].next=head[u];
head[u]=tot;
}
int findroot()
{
for(int i=1;i<=n;++i)
if(!is_h[i])
return(i);
}
void dfs(int k)
{
vis[k]=1;
f[k][0] = 0;
f[k][1] = a[k];//错位1
for(int i=head[k];i;i=e[i].next)
{
if(vis[e[i].to])
continue;
dfs(e[i].to);
f[k][1]+=f[e[i].to][0];
f[k][0]+=max(f[e[i].to][0],f[e[i].to][1]);
}
return;
}
int main()
{
scanf("%d",&n);
for(int i=1;i<=n;++i)
scanf("%d",&a[i]);
for(int i=1;i<n;++i)
{
int l,k;
scanf("%d%d",&l,&k);//错误2
is_h[l]=true;
addedge(k,l);
}
root=findroot();
dfs(root);
printf("%d",max(f[root][0],f[root][1]));
return 0;
}
```
by gmx0424 @ 2023-10-23 17:07:36
@[gmx0424](/user/890233) 给你注释了
by gmx0424 @ 2023-10-23 17:07:55