Add unpaired socks task

src/battle_asserts/issues/unpaired_socks.clj

@@ -0,0 +1,26 @@
+(ns battle-asserts.issues.unpaired-socks
+  (:require [clojure.test.check.generators :as gen]))
+
+(def level :easy)
+
+(def description "\"Where do the socks go?\" - Misha thought after another laundry.
+                 As usual, after the washing, he had a lot of socks left without pair, and he had to decide how many new socks to buy.
+                 He decided to simplify the task and make a machine that would count socks without pairs.
+                 Misha decided to create an algorithm to search for unpaired socks. Help Misha to write an algorithm.
+                 The function accepts an array of `n` integers `X`, - where `X` is the color of the sock from 0 to 1000. ")
+
+(def signature
+  {:input  [{:argument-name "socks" :type {:name "array" :nested {:name "integer"}}}]
+   :output {:type {:name "integer"}}})
+
+(def test-data
+  [{:expected 2 :arguments [[19 20 11 9 20 9]]}
+   {:expected 0 :arguments [[19 19 11 11]]}
+   {:expected 1 :arguments [[19 16 19 11 11]]}])
+
+(defn arguments-generator []
+  (gen/tuple (gen/vector (gen/choose 0 1000) 4 20)))
+
+(defn solution [socks]
+  (count (filter #(= (last %) 1) (frequencies socks))))
+