make-change.clj

(defn make-change [x coinset]
  (loop [x x
         change []]
    (let [possible-coins (take-while #(when (>= x %) %) coinset)
          current-coin (some #(when (zero? (rem x %)) %) possible-coins)]
      (cond
        (= x (reduce + possible-coins))
        (concat possible-coins change)
        (= x 0)
        change
        (nil? current-coin)
        (throw (Exception. "cant make change"))
        :else
        (recur (- x current-coin) (conj change current-coin))
        )
      )
    ))
=> #'user/make-change
(make-change 5 [2 5])
=> (5)
(make-change 6 [2 5])
=> (2 2 2)
(make-change 7 [2 5])
=> (2 5)