Delete a node from linked list specific position in kotlin

Kotlin program for Delete a node from linked list specific position. Here problem description and explanation.

// Kotlin Program for
// Delete node at given index of linked list

// Linked list node
class LinkNode
{
	var data: Int;
	var next: LinkNode ? ;
	constructor(data: Int)
	{
		this.data = data;
		this.next = null;
	}
}
class SingleLL
{
	var head: LinkNode ? ;
	var tail: LinkNode ? ;
	constructor()
	{
		this.head = null;
		this.tail = null;
	}
	// Add new node at the end of linked list
	fun addNode(value: Int): Unit
	{
		// Create a new node
		val node: LinkNode = LinkNode(value);
		if (this.head == null)
		{
			this.head = node;
		}
		else
		{
			this.tail?.next = node;
		}
		this.tail = node;
	}
	// Display linked list element
	fun display(): Unit
	{
		if (this.head == null)
		{
			return;
		}
		var temp: LinkNode ? = this.head;
		// iterating linked list elements
		while (temp != null)
		{
			print(""+ temp.data + " → ");
			// Visit to next node
			temp = temp.next;
		}
		println("NULL");
	}
	// Delete node at given position
	fun deleteAtIndex(index: Int): Unit
	{
		var temp: LinkNode ? = this.head;
		if (this.head == null)
		{
			println("Empty linked list");
			return;
		}
		else if (index < 0)
		{
			println("Invalid positions");
			return;
		}
		else if (index == 1)
		{
			// Means deleting a first node
			if (this.tail == this.head)
			{
				// Only one node
				this.tail = null;
			}
			// Make second node as head
			this.head = this.head?.next;
		}
		else
		{
			var count: Int = index - 1;
			// iterating linked list elements and find deleted node
			while (temp != null && count > 1)
			{
				// Visit to next node
				temp = temp.next;
				count -= 1;
			}
			if (count == 1 && temp?.next != null)
			{
				// Get deleted node
				val n: LinkNode? = temp.next;
				if (n == this.tail)
				{
					// When delete last node
					this.tail = temp;
				}
				// Unlink the deleting node
				temp.next = n?.next;
			}
			else
			{
				println(" Index " + index + " are not present");
				return;
			}
		}
	}
}
fun main(args: Array < String > ): Unit
{
	val sll: SingleLL = SingleLL();
	// Test with your index
	// Note index start with 1
	val index: Int = 5;
	// Linked list
	// 10 → 20 → 30 → 40 → 50 → 60 → 70 → 80 → NULL
	sll.addNode(10);
	sll.addNode(20);
	sll.addNode(30);
	sll.addNode(40);
	sll.addNode(50);
	sll.addNode(60);
	sll.addNode(70);
	sll.addNode(80);
	println(" Before Delete Linked List");
	sll.display();
	// Delete node at 5-th position
	sll.deleteAtIndex(index);
	// Display linked list
	println(" After Delete Linked List");
	sll.display();
}

Output

 Before Delete Linked List
10 → 20 → 30 → 40 → 50 → 60 → 70 → 80 → NULL
 After Delete Linked List
10 → 20 → 30 → 40 → 60 → 70 → 80 → NULL


Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.

New Comment







© 2021, kalkicode.com, All rights reserved