Create sublists of scala list

Question

Input: List(1,2,3)

Expected Output 1: List(1), List(1, 2), List(1,2,3)

Expected Output 2: List(1, 1, 2, 1, 2, 3)

Answer 1

Expected Output 1

val l = List(1,2,3)
l.map( x => (l.head to x).toList)

Expected Output 2

l.flatMap{ x => 
   l.head to x 
}