hdu1520 Anniversary party 树形dp

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

int N,V[6100];
vector<int>son[6010];
int dp[6100][2],vis[6100];

void dfs(int n){
	vis
=1;
	int len=son
.size();
	dp
[1]=V
;
	for(int i=0;i<len;i++){
		int	k=son
[i];
		if(vis[k])	continue;
		dfs(k);
		if(dp
[1]<dp
[1]+dp[k][0])	dp
[1]=dp
[1]+dp[k][0];
		dp
[0]=max(dp
[0],max(dp
[0]+dp[k][1],dp
[0]+dp[k][0]));
	}
}

int main()
{
	int i,j,k,u,v;
	
	while(scanf("%d",&N)!=EOF)
	{
		memset(vis,0,sizeof(vis));
		memset(dp,0,sizeof(dp));
		for(i=1;i<=N;i++){
			scanf("%d",&V[i]);
			son[i].clear();
		}
		while(scanf("%d%d",&u,&v),u||v){
			son[v].push_back(u);
			vis[u]=1;		//非根节点 
		}
		
		
		for(i=1;i<=N;i++)
			if(vis[i]==0){
				memset(vis,0,sizeof(vis));
			//	printf("%d\n",i);
				
				dfs(i);//for(j=1;j<=N;j++)	printf("%d    %d %d\n",j,dp[j][0],dp[j][1]);
			//	printf("%d %d\n",dp[i][0],dp[i][1]);
				printf("%d\n",max(dp[i][0],dp[i][1]));
			}
	}
	return 0;
}
/*
7
1
-1
-1
-1
-1
-1
-1
1 3
2 3
6 4
7 4
4 5
3 5
0 0
*/