Consider the following type defined to represent lists of integers:
trait IList case object Void extends IList case class Cons(x: Int, xs: IList) extends IList
4.1. Implement isEmpty
which checks if a list is empty:
def isEmpty(l: IList): Boolean = ???
4.2. Implement size
which returns the size of the list:
def size(l: IList): Int = ???
4.3. Implement append
which concatenates two lists:
def append(l1: IList, l2: IList): IList = ???
4.4. (!) Implement last
which returns the last element from a list:
def last(l: IList): Int = ???
4.5. (!) Implement reverse
. There are two different ways to implement reverse (with direct and with tail-end recursion). Try both implementations.
def reverse(l: IList): IList = ???
4.6. Implement contains
which checks if an element is a member of a list.
def contains(e: Int, l: IList): Boolean = ???
4.7. Implement max
which returns the largest integer from a list:
def max(l: IList): Int = ???
4.8. Implement take
which returns a new list containing the first n
elements of the original list:
def take(n: Int)(l: IList): IList = ???
4.9. Implement drop
which returns a new list containing the original list without the first n
elements:
def drop(n: Int)(l: IList): IList = ???
4.10. Implement isSorted
which checks if a list is sorted:
def isSorted(l: IList): Boolean = ???
4.11. Implement merge
which merges two sorted lists:
def merge(l1: IList, l2: IList): IList = ???
4.12. Implement mergeSort
which sorts a list:
def mergesort(l: IList) IList = ???