Ch136 (Clojure): Task 1

2 files changed, 17 insertions, 3 deletions

diff --git a/challenge-136/tyler-wardhaugh/clojure/src/tw/weekly/c136/t1.clj b/challenge-136/tyler-wardhaugh/clojure/src/tw/weekly/c136/t1.clj
index 1dfc2ecfb5..dddde5d12f 100644
--- a/challenge-136/tyler-wardhaugh/clojure/src/tw/weekly/c136/t1.clj
+++ b/challenge-136/tyler-wardhaugh/clojure/src/tw/weekly/c136/t1.clj
@@ -6,9 +6,21 @@
 ;;;
 (def DEFAULT-INPUT [8 24])
 
+(defn- power-of-2?
+  "Assuming n is a positive BigInteger, is it a power of 2?"
+  [n]
+  (= (.getLowestSetBit n) (dec (.bitLength n))))
+
+(defn two-friendly?
+  "Determine if two positive integers m and n are two friendly, that is:
+  gcd(m, n) = 2^p where p > 0."
+  [m n]
+  (when-let [gcd (.gcd (biginteger m) (biginteger n))]
+    (and (< 1 gcd) (power-of-2? gcd))))
+
 (defn -main
   "Run Task 1 with a given input M and N, defaulting to the first example from
   the task description."
   [& args]
   (let [[M N] (or (some->> args (map edn/read-string)) DEFAULT-INPUT)]
-    ))
+    (println (if (two-friendly? M N) 1 0))))
diff --git a/challenge-136/tyler-wardhaugh/clojure/test/tw/weekly/c136/t1_test.clj b/challenge-136/tyler-wardhaugh/clojure/test/tw/weekly/c136/t1_test.clj
index c223c2e4fa..cf5b6ea6e0 100644
--- a/challenge-136/tyler-wardhaugh/clojure/test/tw/weekly/c136/t1_test.clj
+++ b/challenge-136/tyler-wardhaugh/clojure/test/tw/weekly/c136/t1_test.clj
@@ -1,7 +1,9 @@
 (ns tw.weekly.c136.t1-test
   (:require [clojure.test :refer [deftest is testing]]
-            [tw.weekly.c136.t1 :refer []]))
+            [tw.weekly.c136.t1 :refer [two-friendly?]]))
 
 (deftest examples
   (testing "Examples from description"
-    ))
+    (is (true? (two-friendly? 8 24)))
+    (is (false? (two-friendly? 26 39)))
+    (is (true? (two-friendly? 4 10)))))