poj 2342 Anniversary party

树状dp搞之。。。

再次吐槽，各种不会dp，惨淡的人生啊！！！

/*
 * Author: stormdpzh
 * Created Time: 2012/7/29 20:45:46
 * File Name: poj_2342.cpp
 */
#include <iostream>
#include <cstdio>
#include <sstream>
#include <cstring>
#include <string>
#include <cmath>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <algorithm>
#include <functional>

#define sz(v) ((int)(v).size())
#define rep(i, n) for(int i = 0; i < n; i++)
#define repf(i, a, b) for(int i = a; i <= b; i++)
#define repd(i, a, b) for(int i = a; i >= b; i--)
#define out(n) printf("%d\n", n)
#define mset(a, b) memset(a, b, sizeof(a))
#define wh(n) while(1 == scanf("%d", &n))
#define whz(n) while(1 == scanf("%d", &n) && n != 0)
#define lint long long

using namespace std;

const int MaxN = 6005;

vector<int> edge[MaxN];
int n;
bool son[MaxN];
int val[MaxN];
int f[MaxN][2];

void gao(int u)
{
    f[u][0] = 0;
    f[u][1] = val[u];
    rep(i, sz(edge[u])) {
        int v = edge[u][i];
        gao(v);
        f[u][1] += f[v][0];
        f[u][0] += max(f[v][0], f[v][1]);
    }
}

int main()
{
    wh(n) {
        for(int i = 1; i <= n; i++) scanf("%d", &val[i]);
        for(int i = 1; i <= n; i++) edge[i].clear();
        int a, b;
        while(2 == scanf("%d%d", &a, &b) && (a || b)) {
            edge[b].push_back(a);
            son[a] = true;
        }
        int root;
        for(int i = 1; i <= n; i++) if(!son[i]) {
            root = i;
            break;
        } 
        gao(root);
        out(max(f[root][0], f[root][1]));
    }
    return 0;
}