day01.rb

# data = DATA.readlines
data = File.readlines(ARGV.first)

p data
  .map(&:chomp)
  .chunk_while { _2 != "" }
  .map { _1.map(&:to_i) }
  .map(&:sum)
  .sort[-3..]
  .sum


__END__
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https://youtu.be/ooqgY9yVbPc

memo = {}
deer = 1
File.readlines('day-1-data.txt').each do |line|
    line.strip!
    if line.empty?
        deer += 1
        next
    end
    memo[deer].nil? ? memo[deer] = Integer(line) : memo[deer] += Integer(line)
end

memo.max_by{|k,v| v}

memo.sort_by(&:last).last(3).map{|k, v| v}.sum

I like yours a lot more 😄