Answers for "cycle detection in linked list"

cycle detection in linked list

class SinglyLinkedListNode:
    def __init__(self, node_data):
        self.data = node_data
        self.next = None

class SinglyLinkedList:
    def __init__(self):
        self.head = None
        self.tail = None

    def insert_node(self, node_data):
        node = SinglyLinkedListNode(node_data)

        if not self.head:
            self.head = node
        else:
            self.tail.next = node


        self.tail = node


def has_cycle(head):
    count = 0
    temp = head
    while temp:
        if count == llist_count + 1:
            return "Cycle detection is Found"
        count += 1
        temp = temp.next
    return "No cycle detection is Found"
    

if __name__ == '__main__':
    index = int(input("Enter the index where the last node need to connected:"))

    llist_count = int(input("Enter the linked list count: "))

    llist = SinglyLinkedList()
    
    print("Enter the element to be added on linked list one by one")
    for _ in range(llist_count):
        llist_item = int(input())
        llist.insert_node(llist_item)

    extra = SinglyLinkedListNode(-1);
    temp = llist.head;

    for i in range(llist_count):
        if i == index:
            extra = temp

        if i != llist_count-1:
            temp = temp.next

    temp.next = extra

    result = has_cycle(llist.head)
    print('\n')
    print('Result: ',result)
    
  '''
  Output window:
  
  Enter the index where the last node need to connected:2
  Enter the linked list count: 3
  Enter the element to be added on linked list one by one
  1
  2
  3


  Result:  Cycle detection is Found
  '''