Add q80

Author: davidkun

src/ex/q080.clj

@@ -0,0 +1,9 @@
+;; https://4clojure.oxal.org/#/problem/080
+ 
+(ns ex.q080)
+
+(defn ans
+  "Problem 80, Perfect Numbers"
+  [x]
+  (letfn [(divisors [y] (->> (range 1 y) (filter #(zero? (mod y %)))))]
+    (= x (apply + (divisors x)))))

test/ex/q080_test.clj

@@ -0,0 +1,13 @@
+;; https://4clojure.oxal.org/#/problem/080
+ 
+(ns ex.q080-test
+  (:require [clojure.test :as t]
+            [ex.q080 :as sut]))
+
+(t/deftest test-q80
+  (t/testing "Problem 80, Perfect Numbers"
+    (t/is (= true (sut/ans 6)))
+    (t/is (= false (sut/ans 7)))
+    (t/is (= true (sut/ans 496)))
+    (t/is (= false (sut/ans 500)))
+    (t/is (= true (sut/ans 8128)))))