stringReduction.rb

def StringReduction(str)

    # code goes here
    hash = {"ab":"c", "ac":"b", "bc":"a",
            "ba":"c", "ca":"b", "cb":"a"}
    count = 0
    while str != str[0]*str.length
        if hash.has_key? :"#{str[count..count+1]}"
            str = str.sub(str[count..count+1], hash[:"#{str[count..count+1]}"])
            count = 0
        else
            count += 1
        end
    end
    return str.length
  
  end

puts(StringReduction("abcabc")) #=>2
puts(StringReduction("abb"))    #=>1
puts(StringReduction("abc"))    #=>2