Mercurial > repos > other > adventofcode2023
view day11.rb @ 21:46fb65f2cb94
Add Day 14 part 1 implementation
If you look at columns and see "how far can this go" then the
weight is just the sum of the partial triangle numbers of
highest_weight to highest_weight minus number of rocks that
can roll up to there.
Part 2 seems to involve actually moving the rocks, though!
author | IBBoard <dev@ibboard.co.uk> |
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date | Sat, 16 Dec 2023 10:29:36 +0000 |
parents | ddb69833346c |
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] OPEN_SPACE = "." GALAXY = "#" input_space = File.open(file, "r").each_line(chomp: true).map(&:each_char).map(&:to_a) first, *rest = input_space open_columns = first.zip(*rest).map {|col| col.all? {|cell| cell == OPEN_SPACE}} expanded_space = input_space.flat_map do |row| new_row = row.zip(open_columns).flat_map {|cell, is_open| is_open ? [cell, cell] : [cell]} if row.all? {|cell| cell == OPEN_SPACE} then [new_row, new_row] else [new_row] end end galaxies = expanded_space.each_with_index.flat_map {|row, y| row.each_with_index.map {|cell, x| [x, y] if cell == GALAXY}}.compact galactic_distances = galaxies.combination(2).map {|a, b| (a[0] - b[0]).abs + (a[1] - b[1]).abs} puts galactic_distances.sum