How to do exponentiation in clojure?

Question

How can I do exponentiation in clojure? For now I\'m only needing integer exponentiation, but the question goes for fractions too.

Answer 1

Try

(defn pow [x n]
  (loop [x x n n r 1]
    (cond
      (= n 0) r
      (even? n) (recur (* x x) (/ n 2) r)
      :else (recur x (dec n) (* r x)))))

for a tail-recursive O(log n) solution, if you want to implement it yourself (only supports positive integers). Obviously, the better solution is to use the library functions that others have pointed out.