Mercurial > repos > other > adventofcode2023
view day13b.rb @ 38:8e92cb172e6b
Output final distance
Also minor code cleanup
author | IBBoard <dev@ibboard.co.uk> |
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date | Fri, 20 Sep 2024 20:30:11 +0100 |
parents | fac484765bc9 |
children |
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#! /usr/bin/env ruby if ARGV.length != 1 abort("Incorrect arguments - needs input file") elsif not File.exist? (ARGV[0]) abort("File #{ARGV[0]} did not exist") end file = ARGV[0] maps = File.open(file, "r").each_line().map(&:chomp).chunk_while {|before, after| before.length == after.length}.filter {|chunk| chunk != [""]}.map {|chunk| chunk.map{|row| row.each_char.to_a}} def count_num_changes(row_a, row_b) row_a.zip(row_b).map {|a,b| (a != b) ? 1 : 0}.sum end def find_imperfect_reflection(data) candidate_start = data.each_cons(2).with_index.flat_map {|vals,idx| count_num_changes(*vals) <= 1 ? [idx] : []} valid_starts = candidate_start.flat_map do |start| pos = start reflected = start + 1 num_changes = count_num_changes(data[pos], data[reflected]) while pos > 0 and reflected < data.length - 1 pos -= 1 reflected += 1 num_changes_in_row = count_num_changes(data[pos], data[reflected]) num_changes += num_changes_in_row break unless num_changes <= 1 end num_changes == 1 ? [start + 1] : [] end valid_starts[0] end puts maps.flat_map {|data| [find_imperfect_reflection(data).to_i * 100, find_imperfect_reflection(data.transpose()).to_i]}.sum