Innova solutions count host number from file and write to other file

innova_hckr_rank.rb

filename = gets.strip
res = []
File.open(filename).each do |line|
  res << line.split(' ').first
end

res_hash = Hash.new(0)
res.each { |i| res_hash[i] += 1 }

text_array = res_hash.to_a.map { |res| res.join(' ') }

out_filename = 'records_'+filename

File.open(out_filename, 'w+') do |file|
  text_array.each { |elem| file.puts(elem) }
end