Mercurial > repos > other > adventofcode2023
annotate day9.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 | 891878e52a31 |
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12
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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 histories = File.open(file, "r").each_line(chomp: true).map {|line| line.split(" ").map(&:to_i)} |
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12 |
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13 def diff_array(arr) |
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14 arr.each_cons(2) |
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15 |
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16 end |
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17 |
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18 predictions = histories.map do |history| |
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19 vals = history |
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20 layers = [history] |
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21 while not vals.all? {|v| v == 0} |
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22 vals = vals.each_cons(2).map {|a,b| b - a} |
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23 layers << vals |
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24 end |
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25 layers.reverse!.each_cons(2).map {|diffs, vals| vals << diffs[-1] + vals[-1]} |
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26 layers[-1][-1] |
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27 end |
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28 |
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29 puts predictions.sum |
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30 # Rest of algorithm here |