Fun

Some problems with a computer science bent that have interested me

Versioning problem

Creating a lexicographically ordered sequences of strings which is also an increasing sequence of numbers.

Keypad codes

What is the quickest way to enter every four digit code into a keypad?

Lossy message passing

Designing a protocol for sending bits over a one-way lossy bit-channel

Mobile phone predictive text

Can we rearrange the letters on mobile phones to reduce ambiguities in predictive text?

How long is a sine wave?