3.9 PAT1020 乙级 python

月饼

kind,weight = input().split()
kind = int(kind)
weight = int(weight)
weights = list(map(float,input().split()))
prices = list(map(float,input().split()))
sprice = []
allweight = 0
total = 0
for i in range(kind):
	sprice.append([[prices[i]/weights[i]],i])
	allweight += weights[i]
sprice.sort(reverse = 1)
if allweight<= weight:
	for i in range(kind):
		total += prices[i]
else:
	for pri,wei in sprice:
		if weights[wei]>weight:
			total += weight*pri[0]
			break
		else:
			total += prices[wei]
			weight = weight-weights[wei]
print('%.2f'%(total))

这个题目的陷阱在于 如果总需求大于总库存的情况

还有就是看了网上的  将输入的所有库存数和总价格变成float型  最后才所有测试点成功  为啥？？？