ex1.clj

;; tree-recursive fibonacci
(defn fib-recur
  [n]
  (cond (= n 0) 0
        (= n 1) 1
        :else (+ (fib-recur (- n 1))
                 (fib-recur (- n 2)))))

;;linear iteration fibonacci
(defn fib-iter
  ([n]
     (fib-iter 1 0 n))
  ([a b count]
     (if (= count 0)
       b
       (recur (+ a b)
              a
              (- count 1)))))