You have a directed connected graph. Write an algorithm that detects any cycle, if one exists, and returns a list of its nodes.

You are given a stream of conversation in a mysterious language from planet Mars. Approximate the set of word vocabulary in this language.

A linked list is given. Write an algorithm that detects whether it's a singly linked list or a circularly linked list.

Write the algorithm that LinkedIn.com uses to tell you how many professionals you have access to.