如何仅在一个变量耗尽后才开始添加到另一个变量？

Question

我正在写一个程序，帮助计算手机计划的账单。我试图做的部分工作是实现一个“免费分钟”和“计费分钟”系统。计费分钟数只能在使用完所有免费分钟数后添加到账单中

每次通话都有一个持续时间（以分钟为单位），每次通话后，我们都会通过上述系统输入通话时间

我是编程新手，我很难找到最有效的方法来实现它

Answer 1

int planMinutes = 500
int planOverageMinutes = 0
int currentTotal = 0
int callDuration = 5
int overage = 0

overage = logCall(currentTotal, callDuration, planMinutes)
planOverageMinutes = planOverageMinutes+overage

def logCall(tMinutes, cDuration, pMinutes):
    int totalMinutes = tMinutes+cDuration
    int overageminutes

    if tMinutes < pMinutes:
        if totalMinutes > pMinutes
            overageMinutes = totalMinutes - pMinutes
        else:
            overageMinutes = 0;
    else totalMinutes > pMinutes:
        overageMinutes = (totalMinutes-tMinutes)
    return overageMinutes #return the overage minutes to log your calls