P2014 Code

P2014

#include <bits/stdc++.h>
using namespace std;

vector<vector<int> > graph;
vector<int> cost;
int n,m;

int f[2005][2005];

int dfs(int node)
{
	int sum=0;
	f[node][1]=cost[node];
	for(vector<int>::iterator i=graph[node].begin();i!=graph[node].end();i++){
		int cnt=dfs(*i);
		sum+=cnt;
		for(int j=m+1;j>=1;j--)
			for(int k=sum;k>=0;k--){
				if(j<k+1) continue;
				f[node][j]=max(f[node][j],f[*i][k]+f[node][j-k]);
			}
	}
	sum++;
	return sum;
}

int main()
{
	scanf("%d%d",&n,&m);
	graph.resize(n+1);cost.resize(n+1);
	for(int i=1;i<=n;i++){
		int father;
		scanf("%d%d",&father,&cost[i]);
		graph[father].push_back(i);
	}
	dfs(0);
	printf("%d\n",f[0][m+1]);
	return 0;
}