Detect and remove loop of linked list in ruby

Ruby program for Detect and remove loop of linked list. Here problem description and other solutions.

#  Ruby program for
#  Detect and remove loop in a linked list

#  Linked list node
class LinkNode 
	# Define the accessor and reader of class LinkNode
	attr_reader :data, :next
	attr_accessor :data, :next
	def initialize(data) 
		self.data = data
		self.next = nil
	end

end

class SingleLL 
	# Define the accessor and reader of class SingleLL
	attr_reader :head
	attr_accessor :head
	def initialize() 
		self.head = nil
	end

	#  Add new node at the end of linked list
	def insert(value) 
		#  Create a node
		node = LinkNode.new(value)
		if (self.head == nil) 
			self.head = node
		else
 
			temp = self.head
			#  Find last node
			while (temp.next != nil) 
				#  Visit to next node
				temp = temp.next
			end
			#  Add node at last position
			temp.next = node
		end
	end

	#  Display all Linked List elements
	def display() 
		if (self.head != nil) 
			temp = self.head
			while (temp != nil) 
				#  Display node value
				print("  ", temp.data)
				#  Visit to next node
				temp = temp.next
			end
		else
			print("Empty Linked list\n")
		end

	end

	#  Delete loop
	def deleteLoop(temp) 
		#  Base condition
		if (temp == nil || temp.next == nil) 
			return nil
		end

		hold = temp.next
		#  Important to break recursion
		temp.next = nil
		temp.next = self.deleteLoop(hold)
		return temp
	end

	#  Detecting loop of linked list
	def detectLoop() 
		if (self.head == nil) 
			print("Empty Linked List \n")
			return
		end

		first = self.head
		second = self.head
		while (second != nil && 
               second.next != nil && 
               second.next.next != nil) 
			#  Visit to next node
			first = first.next
			#  Visit to second next node
			second = second.next.next
			if (first == second) 
				#  loop is found
				print("Loop Found\n")
				#  Then delete loop
				self.deleteLoop(self.head)
				return
			end
		end
		#  When no loop
		print("Loop not exist\n")
	end
end

def main() 
	sll = SingleLL.new()
	#  Linked list
	#  1 → 2 → 3 → 4 → 5 → 6 → 7 → 8 → NULL
	sll.insert(1)
	sll.insert(2)
	sll.insert(3)
	sll.insert(4)
	sll.insert(5)
	sll.insert(6)
	sll.insert(7)
	#  Case A
	#  When no loop
	sll.detectLoop()
	#  Create loop for testing
	sll.head.next.next.next.next.next.next.next = sll.head.next
	#  Case B
	#  When loop
	sll.detectLoop()
	print("Linked List\n")
	#  After remove loop, linked list is
	sll.display()
end

main()

Output

Loop not exist
Loop Found
Linked List
  1  2  3  4  5  6  7