pat 1079

the key point is how to present a tree....data structure

ps:time and space complexity.

#include<iostream>

using namespace std;

struct TreeNode
{
	double price;
	int parent;
	int amount;
};

int main()
{
	const int N=100001;
	TreeNode node[N];
	int n;
	double p,r;
	cin>>n>>p>>r;
	
	for(int i=0;i<n;i++)
	{
		node[i].price=0;
		node[i].amount=0;
	}
	node[0].price=p;
	for(int i=0;i<n;i++)
	{
		int k;
		cin>>k;
		if(k==0)
		{
			cin>>node[i].amount;
		}
		else
		{
			for(int j=0;j<k;j++)
			{
				int x;
				cin>>x;
				node[x].parent=i;
				if(node[i].price!=0)
				{
					node[x].price=node[i].price*(1+r/100);
				}
			}
		}
	}
	double ans=0;
	for(int i=0;i<n;i++)
	{
		if(node[i].price==0)
		{
			node[i].price=node[node[i].parent].price*(1+r/100);
		}
		if(node[i].amount!=0)
		{
			ans+=node[i].price*node[i].amount;
		}
	}
	printf("%.1lf",ans);
}