1020 月饼

题目 

#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
struct ss {
	double sale,price,num;;
};
bool cmp(struct ss a,struct ss b) {
	return a.sale>b.sale;
}
int main () {//贪心策略 
	int n,m;
	cin>>n>>m;
	struct ss s[n];
	for(int i=0; i<n; ++i)
		cin>>s[i].num;
	for(int i=0; i<n; ++i) {
		cin>>s[i].price;
		s[i].sale=1.*s[i].price/s[i].num;
	}
	sort(s,s+n,cmp);
	double ans=0;
	for(auto i : s) {
		if(m-i.num>0) {
			m-=i.num;
			ans+=i.price;
		} else {
			ans+=i.sale*m;
			break;
		}
	}
	printf("%.2lf",ans);
	return 0;
}