In day 6, we’re looking for start of message markers in a series of bytes. ...

Day 2 was a rock-paper-scissors simulator, in an interestingly backwards sense. ...

Day 23 was a twist on the classic Towers of Hanoi puzzle. ...

In day 9, we grouped bounded regions. ...

On Day 8, we reverse a mapping of on/off signals to the 7-segment digits they represent. ...

Day 5 was fundamentally a visual puzzle, anyway. ...

On day 4, we play Bingo with a giant squid. ...