在Java中，如何对一定数量的总金额申请利息

Question

我在Java中有一个问题需要解决。基本上，我必须计算KWH客户上个月到目前为止已经花了多少钱。从0-300 KWH，总计5美元。从301到1000kwh，前300kwh为5美元，然后每kwh额外增加0.03美元。从1001及以上每千瓦时额外收费0.02美元。我不确定如何在300kwh后每千瓦时应用0.03和0.02。感谢。

Answer 1

从5美元开始。这是金额。

If the total is greater than 300 kwh,
  then the amount should be increased by $0.03 per kwh above 300.

If the total is greater than 1000 kwh,
  then the amount should be reduced by $0.01 per kwh above 1000.

从那个伪代码开始。以下是基于您的评论的一些实际代码：

int totalReading = ...;  // something

// $5 is the minimum cost
double cost = 5.0;

// above 300, the cost is 0.03 per
if (totalReading > 300)
  cost += (totalReading - 300) * 0.03;

// above 1000, the cost drops 0.01 per
if (totalReading > 1000)
  cost -= (totalReading - 1000) * 0.01;