1020. 月饼 (25)

#include<iostream>
#include<stdlib.h>
using namespace std;
struct node{
	double num;
	double price;
	double weight;
};
int cmp(const void *a, const void *b){
	node aa = *(node*)a;
	node bb = *(node*)b;
	if (aa.price / aa.num > bb.price / bb.num) return -1;
	else if (aa.price / aa.num < bb.price / bb.num) return 1;
	else return 0;
}
int main(){
	int a, b, cnt = 0;
	double temp = 0;
	cin >> a >> b;
	node mooncake[a];
	for (int i = 0; i < a; i++)cin >> mooncake[i].num;
	for (int i = 0; i < a; i++)cin >> mooncake[i].price;
	for (int i = 0; i < a; i++)mooncake[i].weight = 1.0 * mooncake[i].price / mooncake[i].num;
	qsort(mooncake, a, sizeof(mooncake[0]), cmp);
	while (b != 0 && cnt != a){
		if (b >= mooncake[cnt].num) {
			temp += mooncake[cnt].price;
			b -= mooncake[cnt].num;
			cnt++;
		}
		else{
			temp += b * mooncake[cnt++].weight;
			b = 0;
		}
	}
	printf("%.2f", temp);
	return 0;
}