I was contacted through LinkedIn by a recruiter, which led to an introductory phone call with them. The next step was a coding challenge, given over Google Docs, followed by a conversation with a tech interviewer over the phone. The last round was an onsite, which consisted of five one-hour technical interviews.

You are given four numbers (type int), and have four basic math operators at your disposal (+, -, x, /).

Given arbitrary ways to group the numbers and using any of the operators, determine if you can make the number 24 from the four numbers. The numbers must be processed in the order they appear.