Question

我是第一年的编程学生，我在尝试让我的代码正确循环时遇到了麻烦，我想了解如何让它按照需要运行。我正在运行一个程序，它将使用每个硬币的预设库存计算更改，价格和付款将由用户输入，更改将通过库存中剩余的硬币数量返回。现在我在努力让计划退回资金不足的时候遇到了困难。而且没有变化＆＃39;打印语句，试图让它从四分之一到一角硬币到镍币和硬币正确地循环，我不确定我可能做错了什么。

quarters = 10
dimes = 10
nickels = 10
pennies = 10
stock = quarters, dimes, nickels, pennies
print("\nWelcome to change-making program.")

print("\nStock: {} quarters, {} dimes, {} nickels, and {} pennies".format(
            quarters, dimes, nickels, pennies))
in_str = float(input("Enter the purchase price (xx.xx) or 'q' to quit: "))
payment_int = int(input("Input dollars paid (int):"))
change_sum = float(payment_int) - in_str
#in_str = float(input("Enter the purchase price (xx.xx) or 'q' to quit: "))
while change_sum >= 0:

            if payment_int < in_str:
                print("Insufficient funds")
                break
            elif payment_int == in_str:
                print("No Change")
                break
            else:
                if quarters > 0 and change_sum >= 0.25:

                    change_sum = change_sum - 0.25
                    quarters -= 1

                    print(quarters, change_sum)



                elif dimes > 0 and 0.25 > change_sum >= 0.10:

                    change_sum = change_sum - 0.1
                    dimes -= 1
                    print(dimes, change_sum)
                elif nickels > 0 and 0.1 > change_sum >= 0.05:
                    change_sum = change_sum - 0.05
                    nickels -= 1
                    print(nickels, change_sum)
                elif pennies > 0 and 0.05 > change_sum >= 0.01:
                    change_sum = change_sum -0.01
                    pennies -=1
                    print(pennies, change_sum)
                else:
                    if change_sum == 0.0:

                        break


print("\nStock: {} quarters, {} dimes, {} nickels, and {} pennies".format(
            quarters, dimes, nickels, pennies))
print(change_sum)

Answer 1

如果资金不足，则change_sum为<0且while循环永不运行。这就是为什么你没有得到资金不足的原因＆＃34;信息。您应首先检查充足性，然后开始循环：

只需更改此部分：

while change_sum >= 0:
    if payment_int < in_str:
        print("Insufficient funds")
        break
    elif payment_int == in_str:
        print("No Change")
        break
    else:
        if quarters > 0 and change_sum >= 0.25:

到此：

if payment_int < in_str:
    print("Insufficient funds")
    break
elif payment_int == in_str:
    print("No Change")
    break

while change_sum >= 0:
    if quarters > 0 and change_sum >= 0.25:

无法让此循环正常运行

1 个答案: