Greplin Challenge Solution

After reading this article in Calcalist, I was impressed by the startup and decided to visit greplin.com.
After a quick glance @ the site, I found a very nice programming challenge here.

The challenge consists of 3 levels. Each level is a riddle that needs to be solved by programming. To pass a level, we need to find the correct answer for the riddle, and enter it in the challenge page.

It took me about a hour and change to solve it. It was very fun and I recommend you to try it out :-).

For those who don't feel like busting their brains out for the solutions, here's my code for the solution.

Also here's a screenshot for the simple UI I've created to test the solutions.