Mercurial > repos > other > adventofcode2023
view day1b.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 | 76cc43966538 |
children |
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#! /usr/bin/env ruby if ARGV.length != 1 abort("Incorrect arguments - pass a single file") elsif not File.exist? (ARGV[0]) abort ("File #{ARGV[0]} did not exist") end file = ARGV[0] sum = 0 number_map = { "one" => 1, "two" => 2, "three" => 3, "four" => 4, "five" => 5, "six" => 6, "seven" => 7, "eight" => 8, "nine" => 9 } (1..9).each {|i| number_map[i.to_s] = i} File.open(file, "r").each_line do |line| pos = line.length value_1 = 0 number_map.each do |k,v| index = line.index(k) if index and index < pos value_1 = v pos = index end end pos = line.length line.reverse! value_2 = 0 number_map.each do |k,v| index = line.index(k.reverse) if index and index < pos value_2 = v pos = index end end sum += (value_1 * 10) + value_2 end puts sum