Applied in August. Two weeks later, I got an email asking me to fill out an online questionnaire and take a programming test on Codility. I completed both on the same day.

Another two weeks later, I got another email saying I'm rejected. I have no idea what happened. The programming test had only one question, and it wasn't hard. I'm pretty sure my solution ran well (they don't show you the result, though).

The only thing I can think of is that in the questionnaire, it asks if I had read the two books their CEO wrote, and I chose "No" (it will be a joke if this is true).

Find the number of "similar numbers".