Mercurial > repos > other > adventofcode2023
view day2.rb @ 39:0e17e4bd97a9 default tip
Rewrite as four-dimensional route finding
The grid isn't just a 2D grid. The constraints make it 4D:
* X
* Y
* Last direction
* Number of steps in that direction
By tracking all four dimensions, we can find the shortest route
for _all_ combinations of the constraint. Previously, we were dropping
routes that were currently longer but ended up shorter because
they could take subsequent steps that other routes couldn't.
author | IBBoard <dev@ibboard.co.uk> |
---|---|
date | Sun, 22 Sep 2024 11:30:53 +0100 |
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