[4Clojure]解题记录-#80

Perfect Numbers

 

---

Difficulty:	Medium
Topics:

 

A number is "perfect" if the sum of its divisors equal the number itself. 6 is a perfect number because 1+2+3=6. Write a function which returns true for perfect numbers and false otherwise.

 

(= (__ 6) true)

 

(= (__ 7) false)

 

(= (__ 496) true)

 

(= (__ 500) false)

 

(= (__ 8128) true)

 

解长度：47

#(= (apply + (for [i (range 1 %) :when (= 0 (mod % i))] i)) %)