Implement a singly linked list as a functional data structure in Kotlin. As discussed in
the class, the list should be a sealed class with enclosed classes to construct a list,
including construction of an empty list. The following methods should be available for a
singly linked list:
1. modifyListHead() method to replace the head of the list with a different element. This
function accepts an input list and an input variable, and returns a list where the head of
the input list has been replaced with the input variable. For example, calling
modifyListHead(exList, 10) where exList = (1,2,3,4,5) would return (10,2,3,4,5).
2. dropFromList() method to drop the first n elements from the list. This function accepts
an input list and a value for n, and returns a list with the first n elements dropped. For
example, calling dropFromList(exList,1) where exList = (1,2,3,4,5) would return (2,3,4,5).
3. sumTwoLists() method that accepts two lists and adds corresponding elements of each
list. This function accepts two input lists and returns their sum as illustrated in the
example below. For two input lists (1,2,3) and (4,5,6), this function returns (5,7,9)
4. multiplyTwoLists() method that accepts two lists and multiplies corresponding elements
in the same way sumTwoLists() adds elements of two arrays.
NB:
Solution
that I earlier got showed some errors when tried to run it. I am also sharing the solution below:
sealed class SinglyLinkedList {
object Empty : SinglyLinkedList()
data class Cons(val head: T, val tail: SinglyLinkedList) :
SinglyLinkedList()
}
fun modifyListHead(list: SinglyLinkedList, newHead: T): SinglyLinkedList =
when (list) {
is SinglyLinkedList.Empty -> SinglyLinkedList.Empty
is SinglyLinkedList.Cons -> SinglyLinkedList.Cons(newHead, list.tail)
}
fun dropFromList(list: SinglyLinkedList, n: Int): SinglyLinkedList =
when (list) {
is SinglyLinkedList.Empty -> SinglyLinkedList.Empty
is SinglyLinkedList.Cons -> if (n == 0) list else dropFromList(list.tail, n - 1)
}
fun sumTwoLists(list1: SinglyLinkedList, list2: SinglyLinkedList): SinglyLinkedList =
when {
list1 is SinglyLinkedList.Empty && list2 is SinglyLinkedList.Empty ->
SinglyLinkedList.Empty
list1 is SinglyLinkedList.Empty -> list2
list2 is SinglyLinkedList.Empty -> list1
else -> SinglyLinkedList.Cons(list1.head + list2.head, sumTwoLists(list1.tail, list2.tail))
}
fun multiplyTwoLists(list1: SinglyLinkedList, list2: SinglyLinkedList): SinglyLinkedList =
when {
list1 is SinglyLinkedList.Empty || list2 is SinglyLinkedList.Empty ->
SinglyLinkedList.Empty
else -> SinglyLinkedList.Cons(list1.head * list2.head, multiplyTwoLists(list1.tail,
list2.tail))
}
fun main(){
val exList = linkedListOf(1, 2, 3, 4, 5)
println(exList)
// Output: 1 2 3 4 5
val modifiedList = exList.modifyListHead(10)
println(modifiedList)
// Output: 10 2 3 4 5
val droppedList = exList.dropFromList(1)
println(droppedList)
// Output: 2 3 4 5
val list1 = linkedListOf(1, 2, 3)
val list2 = linkedListOf(4, 5, 6)
val sumList = list.
Organic Name Reactions for the students and aspirants of Chemistry12th.pptx
Implement a singly linked list as a functional data structure in Kot.pdf
1. Implement a singly linked list as a functional data structure in Kotlin. As discussed in
the class, the list should be a sealed class with enclosed classes to construct a list,
including construction of an empty list. The following methods should be available for a
singly linked list:
1. modifyListHead() method to replace the head of the list with a different element. This
function accepts an input list and an input variable, and returns a list where the head of
the input list has been replaced with the input variable. For example, calling
modifyListHead(exList, 10) where exList = (1,2,3,4,5) would return (10,2,3,4,5).
2. dropFromList() method to drop the first n elements from the list. This function accepts
an input list and a value for n, and returns a list with the first n elements dropped. For
example, calling dropFromList(exList,1) where exList = (1,2,3,4,5) would return (2,3,4,5).
3. sumTwoLists() method that accepts two lists and adds corresponding elements of each
list. This function accepts two input lists and returns their sum as illustrated in the
example below. For two input lists (1,2,3) and (4,5,6), this function returns (5,7,9)
4. multiplyTwoLists() method that accepts two lists and multiplies corresponding elements
in the same way sumTwoLists() adds elements of two arrays.
NB:
Solution
that I earlier got showed some errors when tried to run it. I am also sharing the solution below:
sealed class SinglyLinkedList {
object Empty : SinglyLinkedList()
data class Cons(val head: T, val tail: SinglyLinkedList) :
SinglyLinkedList()
}
fun modifyListHead(list: SinglyLinkedList, newHead: T): SinglyLinkedList =
when (list) {
is SinglyLinkedList.Empty -> SinglyLinkedList.Empty
is SinglyLinkedList.Cons -> SinglyLinkedList.Cons(newHead, list.tail)
}
fun dropFromList(list: SinglyLinkedList, n: Int): SinglyLinkedList =
when (list) {
is SinglyLinkedList.Empty -> SinglyLinkedList.Empty
is SinglyLinkedList.Cons -> if (n == 0) list else dropFromList(list.tail, n - 1)
}
fun sumTwoLists(list1: SinglyLinkedList, list2: SinglyLinkedList): SinglyLinkedList =
2. when {
list1 is SinglyLinkedList.Empty && list2 is SinglyLinkedList.Empty ->
SinglyLinkedList.Empty
list1 is SinglyLinkedList.Empty -> list2
list2 is SinglyLinkedList.Empty -> list1
else -> SinglyLinkedList.Cons(list1.head + list2.head, sumTwoLists(list1.tail, list2.tail))
}
fun multiplyTwoLists(list1: SinglyLinkedList, list2: SinglyLinkedList): SinglyLinkedList =
when {
list1 is SinglyLinkedList.Empty || list2 is SinglyLinkedList.Empty ->
SinglyLinkedList.Empty
else -> SinglyLinkedList.Cons(list1.head * list2.head, multiplyTwoLists(list1.tail,
list2.tail))
}
fun main(){
val exList = linkedListOf(1, 2, 3, 4, 5)
println(exList)
// Output: 1 2 3 4 5
val modifiedList = exList.modifyListHead(10)
println(modifiedList)
// Output: 10 2 3 4 5
val droppedList = exList.dropFromList(1)
println(droppedList)
// Output: 2 3 4 5
val list1 = linkedListOf(1, 2, 3)
val list2 = linkedListOf(4, 5, 6)
val sumList = list1.sumTwoLists(list2)
println(sumList)
// Output: 5 7 9
val multiplyList = list1.multiplyTwoLists(list2)
println(multiplyList)
// Output: 4 10 18
}
