aoc2020/day_09/second.rb

26 lines
544 B
Ruby

# frozen_string_literal: true
input = File.readlines('./input').map(&:to_i)
preamble = 25
invalid_num = 21_806_024
input.each_with_index do |_line, i|
next if i < preamble
res = []
range = input[i - preamble, preamble]
range.each_index do |j|
res << range[i..-1] if range[i..-1]&.size.to_i > 1
preamble.times do |k|
res << range[j, k] if range[j, k]&.size > 1
end
end
out = res.uniq.select { |elems| elems.inject(:+) == invalid_num }
next if out.empty?
puts out.flatten.min + out.flatten.max
break
end