How to merge two LinkedLists in Kotlin

How to merge two LinkedLists in Kotlin.

Here's a step-by-step tutorial on how to merge two LinkedLists in Kotlin:

Step 1: Create a Node class

In Kotlin, we'll start by creating a Node class that represents a single node in our LinkedList. Each node will have a value and a reference to the next node.

class Node(var value: Int, var next: Node? = null)

Step 2: Create a LinkedList class

Next, let's create a LinkedList class that will hold our Nodes. This class will have a reference to the head of the LinkedList and will provide methods for adding nodes to the list.

class LinkedList {
    var head: Node? = null

    fun add(value: Int) {
        val newNode = Node(value)
        if (head == null) {
            head = newNode
        } else {
            var currentNode = head
            while (currentNode?.next != null) {
                currentNode = currentNode.next
            }
            currentNode?.next = newNode
        }
    }
}

Step 3: Create a mergeLists function

Now, let's create a function called mergeLists that takes in two LinkedLists as parameters and returns a new merged LinkedList. This function will iterate through both lists, comparing the values of the nodes and merging them into a new list.

fun mergeLists(list1: LinkedList, list2: LinkedList): LinkedList {
    val mergedList = LinkedList()
    var currentNode1 = list1.head
    var currentNode2 = list2.head

    while (currentNode1 != null && currentNode2 != null) {
        if (currentNode1.value <= currentNode2.value) {
            mergedList.add(currentNode1.value)
            currentNode1 = currentNode1.next
        } else {
            mergedList.add(currentNode2.value)
            currentNode2 = currentNode2.next
        }
    }

    while (currentNode1 != null) {
        mergedList.add(currentNode1.value)
        currentNode1 = currentNode1.next
    }

    while (currentNode2 != null) {
        mergedList.add(currentNode2.value)
        currentNode2 = currentNode2.next
    }

    return mergedList
}

Step 4: Test the mergeLists function

Finally, let's create two LinkedLists, add some nodes to them, and merge them using the mergeLists function.

fun main() {
    val list1 = LinkedList()
    list1.add(1)
    list1.add(3)
    list1.add(5)

    val list2 = LinkedList()
    list2.add(2)
    list2.add(4)
    list2.add(6)

    val mergedList = mergeLists(list1, list2)

    var currentNode = mergedList.head
    while (currentNode != null) {
        println(currentNode.value)
        currentNode = currentNode.next
    }
}

This will output:

1
2
3
4
5
6

And that's it! You've successfully merged two LinkedLists in Kotlin. Feel free to modify the code as needed for your specific use case.