Skip to main content

Delete last node of linked list in kotlin

Kotlin program for Delete last node of linked list. Here problem description and explanation.

/*
    Kotlin program for
    Delete the last node of singly 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;
		}
		// Set new last node
		this.tail = node;
	}
	// Display linked list element
	fun display(): Unit
	{
		if (this.head == null)
		{
			println("Empty Linked List");
			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 last node of singly linked list
	fun deleteLastNode(): Unit
	{
		if (this.head == null)
		{
			println("Empty Linked List");
			return;
		}
		else
		{
			var temp: LinkNode ? = this.head;
			var find: LinkNode ? = null;
			// Find second last node
			while (temp?.next != null)
			{
				find = temp;
				temp = temp.next;
			}
			if (find == null)
			{
				// Delete head node of linked list
				this.head = null;
				this.tail = null;
			}
			else
			{
				// Set new last node
				this.tail = find;
				find.next = null;
			}
		}
	}
}
fun main(args: Array < String > ): Unit
{
	val sll: SingleLL = SingleLL();
	// Linked list
	// 1 → 2 → 3 → 4 → 5 → 6 → NULL
	sll.addNode(1);
	sll.addNode(2);
	sll.addNode(3);
	sll.addNode(4);
	sll.addNode(5);
	sll.addNode(6);
	println("Before Delete ");
	sll.display();
	sll.deleteLastNode();
	println("After Delete ");
	sll.display();
}

Output

Before Delete
1 → 2 → 3 → 4 → 5 → 6 → NULL
After Delete
1 → 2 → 3 → 4 → 5 → NULL




Comment

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