gistfile1.rb

a =  ["a2", "f6", "r1", "a2"]
# => ["a2", "f6", "r1", "a2"]
a.each_with_object({}) do |v, h|
  key, value = v.split("")
  h[key] = value
end
# => {"a"=>"2", "f"=>"6", "r"=>"1"}