What is Loop in linked list?
A Loop in a linked list is a condition when a Linked list does not have any end. That means the last pointer does not point to null in case of single and double linked list and to the head of the linked list in case of circluar linked list insted it points to some other node in the linked list.
Is Loop in linked list?
A loop in a linked list is a condition that occurs when the linked list does not have any end. When the loop exists in the linked list, the last pointer does not point to the Null as observed in the singly linked list or doubly linked list and to the head of the linked list observed in the circular linked list.
How do you find the starting point of a loop in a circular linked list?
Below are steps to find the first node of the loop.
- If a loop is found, initialize a slow pointer to head, let fast pointer be at its position.
- Move both slow and fast pointers one node at a time.
- The point at which they meet is the start of the loop.
How to detect loop / cycle in linked list in Java?
If you want to practice data structure and algorithm programs, you can go through data structure and algorithm interview questions. One of the most popular interview question nowadays is “How to detect loop/cycle in LinkedList”. So I thought I should cover this question. This question is more related to data structure.
How to traverse linked list using two pointers?
Traverse linked list using two pointers. Move one pointer(slow_p) by one and another pointer(fast_p) by two. If these pointers meet at the same node then there is a loop. If pointers do not meet then linked list doesn’t have a loop.
How to find a loop in a list?
In the case of the first node of the loop, the second time we traverse it this condition will be true, hence we find that loop exists. If we come across a node that points to null then the loop doesn’t exist. Time complexity: O (n).
How to detect the start of a loop?
To detect the start of the loop, consider the below algorithm. Step 1: Move ‘S’ to the start of the list, but ‘F’ would remain point to node 3. Step 2: Move ‘S’ and ‘F’ forward one node at a time until they meet. Step 3: The node where they meet is the start of the loop. Let’s visualize the above algorithm for more clarity.