words.clj

(defn score
  [word]
  (let [wc (count word)
        uc (count (into #{} (map identity (clojure.string/lower-case word))))]
    {:word word :score (if (= wc uc) wc 0)}))

(defn winner
  [words]
  (let [m (group-by :score (map score words))]
    (m (apply max (keys m)))))

;; (winner (clojure.string/split-lines (slurp "/usr/share/dict/web2")))
;; => [{:word "dermatoglyphics", :score 15}]