I was convinced to apply during a university presentation.

I had a technical phone interview which went well.

Then, I was invited to London for a physical interview.

There, I completed both a technical group interview and a technical interview with a manager.

These went pretty well, but after two days, I was informed by an automatic email that my application was rejected without any further information.

Encode and decode a string given just a function that provides the encoding of a character.

Order numbers in an array according to the number of occurrences. [3 4 3 4 2 1 3 4 2 4] --> [4 4 4 4 3 3 3 2 2 1]