第五题

row = float(input("请输入消费金额："))
x = row
y = 0
discounts = [1, 0.9, 0.8, 0.7]
for i in range(len(discounts)):
    if x > 0:
        if i == len(discounts):
            amount = min(x, len(discounts) - 1)
            y += x * discounts[i]
        else:
            y += min(x, 1000) * discounts[i]
            x -= 1000
print(f"支付金额为：{y}")