scala - 如何获得可被scala中的除数整除的最接近的数字

Question

如何在 scala 中得到能被除数整除的最接近的数。

例如

-if divisor -20 and dividend is 15, the number 15 has to be converted to 20
-if divisor -20 and dividend is 39, the number 39 has to be converted to 40 
-if divisor -20 and dividend is 45, the number 45 has to be converted to 60 
-if divisor -20 and dividend is 60, the number  conversion is not required.

这个我试过了。但它不适用于负数。

def makeNum(num:Double,buc:Int){
if (num % buc == 0) println(num) else
println(  buc * (num/buc).ceil )
}
   makeNum(39,20) --> 40.0 - working
   makeNum(-10,20) --> -0.0 - Not correct

Answer 1

您似乎不需要“最近”的数字，如标题中所述，但实际上需要“下一个”数字，如“远离零”。如果是这样，那么您的原始设计就非常接近了。您只需要考虑符号，如“远离零的方向”。

def makeNum(num :Double, buc :Int) :Double = {
  val sign = if (num*buc < 0) -1 else 1
  buc*sign * (num/buc*sign).ceil
}

makeNum(39,20)    //res0: Double = 40.0
makeNum(-10,20)   //res1: Double = -20.0
makeNum(45, -20)  //res2: Double = 60.0
makeNum(-7, -3)   //res3: Double = -9.0