Mercurial > repos > other > adventofcode2023
annotate day11.rb @ 35:ca54f9702892
Day 24 part 2 instructions and partial solution
author | IBBoard <dev@ibboard.co.uk> |
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date | Thu, 18 Apr 2024 19:54:59 +0100 |
parents | ddb69833346c |
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Implement day 11 distance finding in space
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1 #! /usr/bin/env ruby |
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2 |
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3 if ARGV.length != 1 |
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4 abort("Incorrect arguments - needs input file") |
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5 elsif not File.exist? (ARGV[0]) |
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6 abort("File #{ARGV[0]} did not exist") |
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7 end |
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8 |
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9 file = ARGV[0] |
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10 |
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11 OPEN_SPACE = "." |
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12 GALAXY = "#" |
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13 |
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14 input_space = File.open(file, "r").each_line(chomp: true).map(&:each_char).map(&:to_a) |
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15 |
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16 first, *rest = input_space |
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17 open_columns = first.zip(*rest).map {|col| col.all? {|cell| cell == OPEN_SPACE}} |
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18 |
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19 expanded_space = input_space.flat_map do |row| |
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20 new_row = row.zip(open_columns).flat_map {|cell, is_open| is_open ? [cell, cell] : [cell]} |
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21 if row.all? {|cell| cell == OPEN_SPACE} then [new_row, new_row] else [new_row] end |
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22 end |
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23 |
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24 galaxies = expanded_space.each_with_index.flat_map {|row, y| row.each_with_index.map {|cell, x| [x, y] if cell == GALAXY}}.compact |
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25 galactic_distances = galaxies.combination(2).map {|a, b| (a[0] - b[0]).abs + (a[1] - b[1]).abs} |
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26 puts galactic_distances.sum |