How to group a variable-length, repeating sequence in Scala

Question

I have a collection of ints that repeat themselves in a pattern:

val repeatingSequence = List(1,2,3,1,2,3,4,1,2,1,2,3,4,5)

I\'d like to sec

Answer 1

import scala.collection.mutable.ListBuffer
import scala.collection.breakOut

val repeatingSequence = List(1,2,3,1,2,3,4,1,2,1,2,3,4,5)
val groupedBySequence: List[List[Int]] = repeatingSequence.foldLeft(ListBuffer[ListBuffer[Int]]()) {
  case (acc, 1) => acc += ListBuffer(1)
  case (acc, n) => acc.last += n; acc
}.map(_.toList)(breakOut)