HDU 1520 Anniversary party (树形DP)

转载请注明出处：忆梦http://blog.csdn.net/yimeng2013/article/details/10266765

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
#include<vector>
using namespace std;
#define N 6005
int dp
[2];
struct Node
{
int parent;
vector<int>son;
}Node
;

void dfs(int root)
{
int len = Node[root].son.size();
for(int i = 0; i < len; i++)
dfs(Node[root].son[i]);

for(int i = 0; i < len; i++)
{
dp[root][0] += max(dp[Node[root].son[i]][1],dp[Node[root].son[i]][0]);
dp[root][1] += dp[Node[root].son[i]][0];
}
}

int main ()
{
int n;
while(scanf("%d", &n) != EOF)
{
memset(dp, 0, sizeof(dp));
for(int i = 1; i <= n; i++)
{
scanf("%d", &dp[i][1]);
Node[i].parent = -1;
Node[i].son.clear();
}

int a, b;
while(scanf("%d %d", &a, &b), a+b)
{
Node[a].parent = b;
Node[b].son.push_back(a);
}

int root = 1;
while(Node[root].parent != -1)
root = Node[root].parent;

dfs(root);
printf("%d\n",max(dp[root][1],dp[root][0]));
}
return 0;
}