Advent Of Code 202 - day 9

aoc_2020_day_9.rb

def number_is_not_sum_of_previous_preamble?(index)
  numbers = @numbers[(index - 25)...(index)]
  aim_number = @numbers[index]

  numbers.each do |number_1|
    numbers.each do |number_2|
      combined_number = number_1 + number_2
      return true if combined_number == aim_number
    end
  end

  false
end

def combined_numbers_equals_aim_number(index)
  numbers = @numbers[...(index)]
  aim_number = @numbers[index]

  numbers.each_with_index do |number, end_index|
    combined_number = 0
    start_index = end_index

    while( (combined_number && combined_number <= aim_number ) || start_index >= 0) do
      combined_number = numbers[start_index...end_index].inject(&:+)

      if combined_number == aim_number
        congatiguous_numbers = numbers[start_index...end_index]
        lowest_number = congatiguous_numbers.min
        highest_number = congatiguous_numbers.max

        puts "Numbers are: #{lowest_number} & #{highest_number}"
        puts "Combined: #{lowest_number + highest_number}"
        return
      end

      start_index -= 1
    end
  end
end


@numbers = File.open('input.real.txt').read.split("\n").compact.collect(&:to_i)

@numbers.each_with_index do |number, index|
  next if index < 25

  puts "number is: #{number}" unless number_is_not_sum_of_previous_preamble?(index)

  unless number_is_not_sum_of_previous_preamble?(index)
    combined_numbers_equals_aim_number(index)
  end
end