Created
December 3, 2021 17:20
-
-
Save colintsteele/08888619eb62fc07e3c5dbcadf700aa1 to your computer and use it in GitHub Desktop.
bitmarine
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| test_input = %w[00100 11110 10110 10111 10101 01111 00111 11100 10000 11001 00010 01010] | |
| # puzzle_input <<-BIN | |
| # # your puzzle input pasted here | |
| # BIN | |
| def most_common(list) | |
| count = list.tally | |
| if count.values.uniq.size == 1 # equal number of 1s and 0s | |
| '1' | |
| else | |
| count.max_by(&:last).first | |
| end | |
| end | |
| def gamma(input) | |
| columns = input.first.size | |
| matrix = input.map { |i| i.split('') } | |
| bits = [] | |
| columns.times do |bit_column| | |
| bits << find_common(matrix.map {|b| b[bit_column]}) | |
| end | |
| bits.join | |
| end | |
| def epsilon(g) | |
| ones = g.length.times.map{"1"}.join | |
| ("%0#{g.length}b" % (Integer("0b#{g}") ^ Integer("0b#{ones}"))) | |
| end | |
| def power_output(binaries) | |
| gams = gamma(binaries) | |
| eps = epsilon(gams) | |
| Integer("0b#{eps}") * Integer("0b#{gams}") | |
| end | |
| #part 2 methods | |
| def o2_info(input, but_which_o2: :c) | |
| columns = input.first.size | |
| matrix = input.map { |i| i.split('') } | |
| accepted = matrix.dup | |
| columns.times do |bit_column| | |
| bit = most_common(accepted.map{ |b| b[bit_column] }) | |
| if but_which_o2 == :c | |
| accepted.reject! {|bs| bs[bit_column] == bit } | |
| else | |
| accepted.select! {|bs| bs[bit_column] == bit } | |
| end | |
| return accepted.join if accepted.size == 1 | |
| end | |
| accepted.first.join # probably not necessary | |
| end | |
| def life_support(binaries) | |
| co2 = o2_info(binaries, but_which_o2: :c) | |
| o2 = o2_info(binaries, but_which_o2: :o) | |
| Integer("0b#{co2}") * Integer("0b#{o2}") | |
| end | |
| power_output puzzle_input # part 1 solution | |
| life_support puzzle_input # part 2 solution |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment