Task

For each number list of 6-digit SEDOLs, calculate and append the checksum digit.



That is, given this input:

710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030

Produce this output:

7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842
B0YBKT7
B000300

Extra credit

Check each input is correctly formed, especially with respect to valid characters allowed in a SEDOL string.



Related tasks

   Luhn test
   ISIN


(defn sedols [xs]
  (letfn [(sedol [ys] (let [weights [1 3 1 7 3 9]
                            convtonum (map #(Character/getNumericValue %) ys)
                            check (-> (reduce + (map * weights convtonum)) (rem 10) (->> (- 10)) (rem 10))]
                        (str ys check)))]
    (map #(sedol %) xs)))