【pat】b1020 月饼

#include<stdio.h>
#include<algorithm>
using namespace std;
const int maxn = 1000;
typedef struct yuebing {
   double cun;
  double shouyi;
   double danjian;
}yue;
yue arr[maxn];
bool cmp(yue a, yue b) {
  return a.danjian>b.danjian;
}
int main()
{
  int N, D; double shoushou = 0;
   scanf("%d%d", &N, &D);
   //输入库存
   for (int i = 0; i<N; i++) {
       scanf("%lf", &arr[i].cun);
   }
    //输入收益，并计算单收益
    for (int i = 0; i<N; i++) {
       scanf("%lf", &arr[i].shouyi);
        arr[i].danjian = arr[i].shouyi / arr[i].cun;
 }
    sort(arr, arr + N, cmp);//根据但收益排序
    for (int i = 0; i<N; i++) {
       if (arr[i].cun >= D) {
            shoushou += arr[i].danjian*D;
            break;
       }
        if (arr[i].cun<D)
         shoushou += arr[i].shouyi;
       D -= arr[i].cun;
 }
    printf("%.2f", shoushou);
    return 0;
}