ciniglio

LIST = [['A','B','C'], ['A','C','E'], ['E','F','D'],['D','A','J'],['E','D','J']]
out = Hash.new(0)
LIST.each do |row|
  arr = row.sort + row.sort
  3.times { out[[arr.shift,arr.shift].sort] += 1 }
end
for key in out.keys.sort do
  puts "#{key.join(", ")}, #{out[key]}"
end