Mercurial > repos > other > adventofcode2023
view day9b.rb @ 13:7826431dbc4f
Finish day 5 part 2 - seeds with ranges
There must be a cleaner method, but this works for splitting
ranges when there's a partial overlap. An interim version
dropped ranges because we were iterating over an array while
also deleting items from it.
author | IBBoard <dev@ibboard.co.uk> |
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date | Sat, 09 Dec 2023 19:53:22 +0000 |
parents | 891878e52a31 |
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] histories = File.open(file, "r").each_line(chomp: true).map {|line| line.split(" ").map(&:to_i)} def diff_array(arr) arr.each_cons(2) end predictions = histories.map do |history| vals = history layers = [history] while not vals.all? {|v| v == 0} vals = vals.each_cons(2).map {|a,b| b - a} layers << vals end layers.reverse!.each_cons(2).map {|diffs, vals| vals.insert(0, vals[0] - diffs[0])} layers[-1][0] end puts predictions.sum # Rest of algorithm here