2.2 KiB
--- Day 1: Not Quite Lisp ---
Santa was hoping for a white Christmas, but his weather machine's "snow" function is powered by stars, and he's fresh out! To save Christmas, he needs you to collect fifty stars by December 25th.
Collect stars by helping Santa solve puzzles. Two puzzles will be made available on each day in the Advent calendar; the second puzzle is unlocked when you complete the first. Each puzzle grants one star. [Good luck!]{title="Also, some puzzles contain Easter eggs like this one. Yes, I know it's not traditional to do Advent calendars for Easter."}
Here's an easy puzzle to warm you up.
Santa is trying to deliver presents in a large apartment building, but
he can't find the right floor - the directions he got are a little
confusing. He starts on the ground floor (floor 0) and then follows
the instructions one character at a time.
An opening parenthesis, (, means he should go up one floor, and a
closing parenthesis, ), means he should go down one floor.
The apartment building is very tall, and the basement is very deep; he will never find the top or bottom floors.
For example:
(())and()()both result in floor0.(((and(()(()(both result in floor3.))(((((also results in floor3.())and))(both result in floor-1(the first basement level).)))and)())())both result in floor-3.
To what floor do the instructions take Santa?
--- Part Two ---
Now, given the same instructions, find the position of the first
character that causes him to enter the basement (floor -1). The first
character in the instructions has position 1, the second character has
position 2, and so on.
For example:
)causes him to enter the basement at character position1.()())causes him to enter the basement at character position5.
What is the position of the character that causes Santa to first enter the basement?
Both parts of this puzzle are complete! They provide two gold stars: **
At this point, you should return to your Advent calendar and try another puzzle.
If you still want to see it, you can get your puzzle input.