L2-003 月饼

背包。

#include <bits/stdc++.h>
using namespace std;
struct node{
	double kc,sj;
	double avg;
}s[1010];
bool cmp(node n1,node n2){
	return n1.avg>n2.avg;
}
int main(){
	int n,total;
	cin>>n>>total;
	for(int i=0;i<n;i++){
		cin>>s[i].kc;
	}
	for(int i=0;i<n;i++){
		cin>>s[i].sj;
		double avs=1.0*s[i].sj/s[i].kc;
		s[i].avg=avs;
	}
    sort(s,s+n,cmp);
    int rest=total;//剩余的月饼量 
    double money=0;
    int idx=0;
    for(int i=0;i<n;i++){
    	if(rest-s[i].kc>=0){
    		rest-=s[i].kc;
    		money+=s[i].sj;
		}else{
			money=money+s[i].avg*rest;
			break;
		}
	}
	printf("%.2f",money);
	return 0;
}