A linked list is a linear data structure in computer science responsible for providing constant time addition, and deleting elements. The linked list consists of a sequence of nodes, each node contains a value and a reference (called a “link”) to the next node in the same series.
Error – Found Cycle in the ListNode
The error – found cycle in the ListNode occurs if there is a problem with a linked list data structure, the case where a node in the list has a reference to another node earlier in the list, thereby creating a cycle. This cycle can cause problems when repeating the list, because the algorithm will never reach the end of the list and will end up in an infinite loop.
The below algorithmic code can generate an error – found cycle in the ListNode in a linked list data structure.
odd = head even = head.next while odd: if odd.next and odd.next.next: odd.next = odd.next.next odd = odd.next else: break odd.next = even
From these examples, you can see we are trying to split a linked list into two separate lists:
One containing the odd-numbered nodes
The other containing the even-numbered nodes
The above code has a problem, the same linked list is used for both the odd and even lists. If you try to modify the list by changing the next pointers of the nodes, it will cause errors if you try to iterate the list again after the changes, because the structure of the list has been altered.
How to fix the Error – found cycle in the ListNode
In order To fix the error – found cycle in the ListNode issue; you have to create two separate linked lists for the odd and even nodes. Then add the nodes to the appropriate list while you iterate through an original linked list.
Here’s an example to help you fix the issue.
odd_list = ListNode(None) even_list = ListNode(None) odd_tail = odd_list even_tail = even_list current = head is_odd = True while current: if is_odd: odd_tail.next = current odd_tail = current
even_tail.next = current even_tail = current is_odd = not is_odd current = current.next odd_tail.next = None even_tail.next = None odd_head = odd_list.next even_head = even_list.next
Let me explain this algorithm.
Two separate lists for the odd and even nodes were created, and later the nodes were added to the appropriate list, and iterate through the original list.
This lists also sets the next pointers of the last nodes in the odd and even lists to None to avoid creating a cycle, leading to the “error – found cycle in the ListNode”..
This approach proves efficient in solving the “error – found cycle in the ListNode”.