How to find middle element of LinkedList in Java in one pass

How do you find middle element of LinkedList in one pass is a programming question often asked Java and non-Java programmers in telephonic Interview. This question is similar to checking palindrome or calculating the factorial, where Interviewer sometimes also ask to write code. In order to answer this question candidate must be familiar with LinkedList data structure i.e. In the case of singly LinkedList, each node of Linked List contains data and pointer, which is the address of next Linked List and the last element of Singly Linked List points towards the null. Since in order to find middle element of Linked List you need to find the length of LinkedList, which is counting elements till end i.e. until you find the last element of Linked List. What makes this data structure Interview question interesting is that you need to find middle element of LinkedList in one pass and you don’t know the length of LinkedList. This is where candidates logical ability puts into the test,  whether he is familiar with space and time trade off or not etc.

Read more »