Skip to main content

insert node at beginning of circular linked list in swift

Swift program for insert node at beginning of circular linked list. Here problem description and explanation.

import Foundation
// Swift 4 Program 
// Insert node at beginning of circular linked list

// Define class of linked list Node
class LinkNode
{
	var data: Int;
	var next: LinkNode? ;
	init(_ data: Int, _ first: LinkNode? )
	{
		self.data = data;
		self.next = first;
	}
}
class CircularLinkedList
{
	var head: LinkNode? ;
	// Class constructors
	init()
	{
		self.head = nil;
	}
	// Insert node at begining of circular linked list
	func insert(_ value: Int)
	{
		// Create a node
		let node: LinkNode? = LinkNode(value, self.head);
		if (self.head == nil)
		{
			// First node of linked list
			self.head = node;
			node!.next = self.head;
		}
		else
		{
			var temp: LinkNode? = self.head;
			// Find the last node
			while (!(temp!.next === self.head))
			{
				// Visit to next node
				temp = temp!.next;
			}
			// Add node
			temp!.next = node;
			// make new head node
			self.head = node;
		}
	}
	// Display node element of circular linked list
	func display()
	{
		if (self.head == nil)
		{
			print("Empty Linked List");
		}
		else
		{
			print("Linked List Element : ");
			// Get first node
			var temp: LinkNode? = self.head;
			// iterate linked list
			while (temp  != nil)
			{
				// Display node
				print(temp!.data, terminator: "  ");
				// Visit to next node
				temp = temp!.next;
				if (temp === self.head)
				{
					// Stop iteration
					return;
				}
			}
		}
	}
	static func main(_ args: [String])
	{
		let task: CircularLinkedList? = CircularLinkedList();
		// Add following linked list nodes
		task!.insert(8);
		task!.insert(7);
		task!.insert(6);
		task!.insert(5);
		task!.insert(4);
		task!.insert(3);
		task!.insert(2);
		task!.insert(1);
		// Display node
		task!.display();
	}
}
CircularLinkedList.main([String]());

Output

Linked List Element :
1  2  3  4  5  6  7  8




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