view day6.rb @ 30:6de4f4d5404d

Implement Day 21 "possible spaces in a maze" Part 2 needs something like "find the repeats and lowest common multiple" that I'm not bothering with
author IBBoard <dev@ibboard.co.uk>
date Wed, 03 Jan 2024 12:01:18 +0000
parents 51e5f26dc81e
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]

times, distances = File.open(file, "r").each_line(chomp: true).map {|v| puts v; puts v.split(":"); v.split(":")[1].split(" ").map(&:to_i)}
events = times.zip(distances)

product = events.map do |event|
	mid = (event[0].to_f / 2).floor
	first_success = (1..mid).bsearch {|i| (event[0] - i) * i > event[1]}
	num_success = (mid - first_success + 1) * 2
	event[0].odd? ? num_success : num_success - 1
end.reduce(:*)

puts product