hozumi

(use 'clojure.contrib.str-utils)

(def digits {"零" 0 "一" 1 "二" 2 "三" 3 "四" 4 "五" 5 "六" 6 "七" 7 "八" 8 "九" 9})

(defn- str-first [s]
  (str (.charAt s 0)))

(defn- trans-ichi [s]
  (let [n (re-find #"[一二三四五六七八九]$" s)]
    (if (nil? n) 0 (digits n))))

hozumi

(use '[clojure.test])
(defn powerset
  ([ls] (lazy-seq (cons () (powerset '(()) ls))))
  ([acc ls]
     (if (empty? ls)
       ()
       (let [fs (first ls)
	     added (map #(conj % fs) acc)]
	 (lazy-cat added
		 (powerset (concat acc added) (rest ls)))))))

hozumi

(defn sha1-str [s]
  (->> (-> "sha1"
           java.security.MessageDigest/getInstance
           (.digest (.getBytes s)))
       (map #(.substring
              (Integer/toString
               (+ (bit-and % 0xff) 0x100) 16) 1))
       (apply str)))