view day2.rb @ 18:ddb69833346c

Implement day 11 distance finding in space "shortest distance" is simplified by it being cardinal directions, so it's the same as taking the right-angle between them. The Part 1 space expansion was quite clean, but the Part 2 approach generalises it to something even nicer.
author IBBoard <dev@ibboard.co.uk>
date Mon, 11 Dec 2023 20:08:47 +0000
parents 49dd1ae93696
children
line wrap: on
line source

#! /usr/bin/env ruby

if ARGV.length != 4
        abort("Incorrect arguments - needs numbers for Red, Green and Blue then input file")
elsif not File.exist? (ARGV[3])
	abort("File #{ARGV[3]} did not exist")
end

max_colours = {
	"red" => ARGV[0].to_i,
	"green" => ARGV[1].to_i,
	"blue" => ARGV[2].to_i
}
file = ARGV[3]

sum = 0
File.open(file, "r").each_line do |line|
	game, all_picks = line.split(":")
	all_valid = all_picks.split(";").all? do |pick|
		pick.split(",").all? do |colour_pick|
			num_picked, colour_picked = colour_pick.strip.split(" ")
			# The last line of a Ruby block is the return value
			num_picked.to_i <= max_colours[colour_picked]
		end
	end
	if all_valid
		puts game
		sum += game.split(" ")[1].to_i
	end
end

puts sum