如何在clojure中求幂？

本文介绍了如何在clojure中求幂？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

如何在clojure中进行取幂运算？ 现在我只需要整数求幂，但问题也是分数。

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

推荐答案

经典递归（看这个，打击堆叠）

classic recursion (watch this, it blows stack)

(defn exp [x n] (if (zero? n) 1 (* x (exp x (dec n)))))

尾递归

(defn exp [x n] (loop [acc 1 n n] (if (zero? n) acc (recur (* x acc) (dec n)))))

功能

(defn exp [x n] (reduce * (repeat n x)))

< sneaky（也打击堆栈，但不是那么容易）

sneaky (also blows stack, but not so easily)

(defn exp-s [x n] (let [square (fn[x] (* x x))] (cond (zero? n) 1 (even? n) (square (exp-s x (/ n 2))) :else (* x (exp-s x (dec n))))))

library

(require 'clojure.contrib.math)