most_common_letter_02.rb

def most_common_letter(string)
  h = Hash.new
  string.chars.sort.each do |c|
    h[c] = 0 if (h[c].nil?)
    h[c] = h[c] + 1
  end
  maxk = nil
  maxv = -1
  mk = h.keys
  mk.each do |k|
    if (h[k] > maxv) then
      maxk = k
      maxv = h[k]
    end
  end
  [ maxk , maxv ]
end