LinkedLists

Question 1

How to reverse linked list using O(1) space?

Answer 1

Using three pointers, curr, next and prev

https://leetcode.com/problems/reverse-linked-list/submissions/

Question 2

How to find middle of the linked list ?

Answer 2

Using fast/slow pointer technique.

https://leetcode.com/problems/middle-of-the-linked-list/