Solution for chuck_norris problem from codingame in scala.

chuck_norris.scala

// https://www.codingame.com/training/easy/chuck-norris 
import math._
import scala.util._

/**
 * Auto-generated code below aims at helping you parse
 * the standard input according to the problem statement.
 **/
object Solution extends App {
    val message = readLine
    val messageBinary = message.map(x => BigInt(x).toString(2).reverse.padTo(7, "0").reverse.mkString("")).mkString("")

    def binaryCounter(num: Char, restMessage: String): (Char, Int, String) = {
        if (restMessage == null || !restMessage.nonEmpty) {
            (num, 0, null)
        } else if (restMessage.head == num) {
            val t: (Char, Int, String) = binaryCounter(num, restMessage.tail)
            (t._1, t._2 + 1, t._3)
        } else {
            (num, 0, restMessage)
        }
    }

    def getGroupings(message: String): List[(Char, Int)] = {
        if (message == null) {
            List()
        } else {
            val t: (Char, Int, String) = binaryCounter(message.head, message)
            (t._1, t._2) :: getGroupings(t._3)
        }
    }

    def encodeGroup(group: (Char, Int)) = {
        val (num, count) = group
        val header = if (num == '0') {
            "00"
        } else {
            "0"
        }

        val code = (1 to count).map(_ => "0").mkString("")
        header + " " + code
    }

    println(getGroupings(messageBinary).map(encodeGroup).mkString(" "))
}