Question

我试着写一个小程序来计算（非常）简单的等式

Revenue = Costs * (1 + Profitpercentage)

例如，121 = 110 *（1 + .10），当缺少3个元素中的任何一个且只有一个时。

我想出了：

puts "What is your Revenue ?"
inputRevenue = gets
puts "What are your Costs ?"
inputCosts = gets
puts "What is your Profit percentage ?"
inputProfitpercentage = gets

revenue = inputRevenue.to_f
costs = inputCosts.to_f
profitpercentage = inputProfitpercentage.to_f

case
       when (revenue == nil) then 
       puts "Your Revenue is : #{costs * (1 + profitpercentage)}"       
       when (costs == nil) then
       puts "Your Costs are : #{revenue / (1 + profitpercentage)}"
       else (profitpercentage == nil)
       puts "Your Profit percentage is : #{(revenue / costs) - 1}"
end

要指定要计算的元素，我只需跳过答案（我只输入Enter）。

适用于Profitpercentage未知。

如果Costs未知，则会显示：

您的利润百分比是：无限

如果Revenue未知，则会显示：

您的利润百分比是：-1.0

我哪里出错了？（此外，它很笨拙......）

Answer 1

您不应该使用nil。只需将nil替换为0。

这里你应该做什么，它会对你有用：

puts "What is your Revenue ?"
inputRevenue = gets
puts "What are your Costs ?"
inputCosts = gets
puts "What is your Profit percentage ?"
inputProfitpercentage = gets

revenue = inputRevenue.to_f
costs = inputCosts.to_f
profitpercentage = inputProfitpercentage.to_f

case
       when (revenue == 0) then 
       puts "Your Revenue is : #{costs * (1 + profitpercentage)}"       
       when (costs == 0) then
       puts "Your Costs are : #{revenue / (1 + profitpercentage)}"
       else (profitpercentage == 0)
       puts "Your Profit percentage is : #{(revenue / costs) - 1}"
end

Answer 2

input = []
puts "What is your Revenue ?"
input << gets.chomp      # get rid of carriage returns
puts "What are your Costs ?"
input << gets.chomp
puts "What is your Profit percentage ?"
input << gets.chomp

input.map! do |rcp| 
  rcp.strip.empty? ? nil : rcp.to_f
end

case
  when input[0].nil? 
    puts "Your Revenue is : #{input[1] * (1 + input[2])}"       
  when input[1].nil?
    puts "Your Costs are : #{input[0] / (1 + input[2])}"
  when input[2].nil?
    puts "Your Profit percentage is : #{(input[0] / input[1]) - 1}"
  else
    puts "Oooups. Entered everything."
end

Ruby case语句，用于非常简单的求解器

2 个答案: