用clojure解决euler problem 9

问题描述：

A Pythagorean triplet is a set of three natural numbers, a  b  c, for which,

a² + b² = c²

For example, 3² + 4² = 9 + 16 = 25 = 5².

There exists exactly one Pythagorean triplet for which a + b + c = 1000.
Find the product abc.

解决方案：

(ns euler-problem-9.core)(defn square  [n]  (* n n))(defn pythagorean-triplet-sum-1000  []  (loop [a 1 b 1]    (if (= (+ (square a) (square b)) (square (- 1000 a b)))      (* a b (- 1000 a b))      (if (and (= a 333) (= b 499))        "no answer"        (if (= b 499)          (recur (inc a) 1)          (recur a (inc b)))))))(pythagorean-triplet-sum-1000)(defn pythagorean-triplet-sum-1000-a-b-c  []  (loop [a 1 b 1]    (if (= (+ (square a) (square b)) (square (- 1000 a b)))      (list a b (- 1000 a b))      (if (and (= a 333) (= b 499))        "no answer"        (if (= b 499)          (recur (inc a) 1)          (recur a (inc b)))))))(pythagorean-triplet-sum-1000-a-b-c)

abc的乘积为：31875000

a，b，c分别为200，375 ，425