PAT 1020 月饼

#include<stdio.h>
#include<algorithm>
using namespace std;

struct yue
{
    double storage;
    double sumprice;
    double price;
};
bool comp(yue a,yue b)
{
    return a.price>=b.price;
}
int main()
{
    int a;//种类
    int b;//需求量 
    int i;
    int cnt,sum,sum3;
    double sum2=0;
    yue d[1000];
    scanf("%d%d",&a,&b);
    for(i=0;i<a;i++){
        scanf("%lf",&d[i].storage);
    }
    for(i=0,sum3=0;i<a;i++){
        scanf("%lf",&d[i].sumprice);
        d[i].price=d[i].sumprice/d[i].storage;
        sum3+=d[i].sumprice;
    }
    sort(d,d+i,comp);
    for(i=0,cnt=0,sum=d[0].storage;i<a;i++){
        if(b<sum) break;
        cnt++;
        sum+=d[i+1].storage;
    }
    if(sum<b)
    printf("%d.00\n",sum3);
    else{
        for(i=0;i<cnt;i++){
        sum2+=d[i].sumprice;    
        b-=d[i].storage;
    }
    sum2+=b*d[i].price;
    printf("%.2f\n",sum2);

    }
    return 0;
 }