# Problem Definition

## Description

Given a linked list, determine if it has a cycle in it.

Follow up: Can you solve it without using extra space?

## Notes

1. [SO post](https://stackoverflow.com/questions/494830/how-to-determine-if-a-linked-list-has-a-cycle-using-only-two-memory-locations)
1. [Stephen Ostermiller blog](https://blog.ostermiller.org/find-loop-singly-linked-list)
1. [LeetCode discussion - O(1) Space Solution](https://leetcode.com/explore/interview/card/top-interview-questions-easy/93/linked-list/773/discuss/44489/O(1)-Space-Solution)