Snippet

advent_of_code/2024_5.rb

Code:

# Advent of Code 2024, Day 5: Print Queue

# https://adventofcode.com/2024/day/5

require_relative './helpers.rb'

def is_valid?(b, r)
  r.map { |i, j| [b.ix(i), b.ix(j)].compact.as { |c| c.size == 2 ? c == c.sort : 1 } }.all?
end

def part_one(bs, r)
  bs.filter { |b| is_valid?(b, r) }.map { |b| b[b.size / 2] }.sum
end

def part_two(bs, r)
  bs.reject { |b| is_valid?(b, r) }.map { |b|
    (0...b.size).each { |i| (i + 1...b.size).each { |j| b[i], b[j] = b[j], b[i] if r.has? [b[j], b[i]] } }
    b[b.size / 2]
  }.sum
end

def solve(data)
  b = data.filter { |l| l.has?(',') }.map { |l| l.split(',').map(&:to_i) }
  r = data.filter { |l| l.has?('|') }.map { |l| l.split('|').map(&:to_i) }
  [part_one(b, r), part_two(b, r)]
end

puts solve(get_dataset(year: 2024, day: 5, type: 'example'))
puts solve(get_dataset(year: 2024, day: 5, type: 'input'))

Output: