ruby: how to find non-unique elements in array and print each with number of occurrences?

Question

I have

a = [\"a\", \"d\", \"c\", \"b\", \"b\", \"c\", \"c\"]

and need to print something like (sorted descending by number of occurrences)

Answer 1

How about:

a.sort.chunk{|x| a.count(x)}.sort.reverse.each do |n, v|
  puts "#{v[0]}:#{n}" if n > 1
end