Btukfyl

I have a mutuable set and assigning the values to it from input

var set = scala.collection.mutable.Set[Int]()
set ++= (in.readLine().split(" ").map(_.toInt))

Input:

1 5

Actual Output:

1,5

Required Output:

1,2,3,4,5

If have used flatMap with condition, but got error. How to achieve this with flatMap

My opinion is, there is no need for flatMap operation here. You might have received compiler error saying invalid syntax. yet i'm going ahead and give you the solution if I really understand your question.

    val in = "1 5"

    var set = scala.collection.mutable.Set[Int]()

    set.++=(in.split(" ").flatMap(value => Set(value.trim.toInt)))



   val range = set.head to set.last

   println( range.mkString(","))

Result
1,2,3,4,5

You might have noticed that only change I had done is , return the value in Set(_).
The nature of the flatMap operation is, it flats multiple collections into single collection hence I'm returning it as Set(_)

An easiest alternative I would think of is

    val in = "1 5"

    val split = in.split(" ")

    val range = split(0).trim.toInt to split(1).trim.toInt

    println(range.mkString(","))

I assume you have always a String like '2 5' as Input:

The solution could look like:

def toSeq(value: String): Seq[Int] = {

  value.split(" ")

  .map(_.toInt).toList match {

    case x1::x2::_ => x1 to x2

    case other => Nil// handle Exception

  }

}

println(toSeq("1 5").toList)

Be aware that the input is not validated!