Ch129 (Clojure): Task 2

3 files changed, 31 insertions, 10 deletions

diff --git a/challenge-129/tyler-wardhaugh/clojure/README.md b/challenge-129/tyler-wardhaugh/clojure/README.md
index 4bb10cd198..3a1ae7a3bb 100644
--- a/challenge-129/tyler-wardhaugh/clojure/README.md
+++ b/challenge-129/tyler-wardhaugh/clojure/README.md
@@ -27,9 +27,9 @@ Run Task #1 with input
 
 Run Task #2 with input:
 
-    $ clojure -M -m tw.weekly.c128.t2 A D 
+    $ clojure -M -m tw.weekly.c128.t2 L1 L2
     # ... or ...
-    $ bb run task-2 A D
+    $ bb run task-2 L1 L2
 
 View available tasks Babashka can run:
 
diff --git a/challenge-129/tyler-wardhaugh/clojure/src/tw/weekly/c129/t2.clj b/challenge-129/tyler-wardhaugh/clojure/src/tw/weekly/c129/t2.clj
index 39275957c2..f1aa677745 100644
--- a/challenge-129/tyler-wardhaugh/clojure/src/tw/weekly/c129/t2.clj
+++ b/challenge-129/tyler-wardhaugh/clojure/src/tw/weekly/c129/t2.clj
@@ -1,14 +1,33 @@
 (ns tw.weekly.c129.t2
-  (:require [clojure.edn :as edn]))
+  (:require [clojure.edn :as edn]
+            [clojure.pprint :refer [cl-format]]))
 
 ;;;
 ; Task description for TASK #2, Add Linked Lists
 ;;;
-(def DEFAULT-INPUT [])
+
+; Traditionally, in Lisps the standard list is a linked list; therefore the
+; core language (and standard library) contain a multitude of functions for
+; dealing with them. In that vein, we'll use the built-in list for this task.
+(def DEFAULT-INPUT ['(1 2 3) '(3 2 1)])
+
+(defn list->num
+  [coll]
+  (->> (map * (reverse coll) (iterate #(* 10 %) 1))
+       (reduce +)))
+
+(defn num->list
+  [n]
+  (->> n str (map #(Character/digit % 10))))
+
+(defn add-lists
+  [& colls]
+  (-> (transduce (map list->num) + colls)
+      num->list))
 
 (defn -main
-  "Run Task 1 with a given input L, defaulting to the first example from the
-  task description."
+  "Run Task 1 with a given inputs L1 and L2, defaulting to the first example
+  from the task description."
   [& args]
-  (let [[L] (or (some->> args (map edn/read-string)) DEFAULT-INPUT)]
-    ))
+  (let [[L1 L2] (or (some->> args (map edn/read-string)) DEFAULT-INPUT)]
+    (cl-format true "~{~a~^ -> ~}~%" (add-lists L1 L2))))
diff --git a/challenge-129/tyler-wardhaugh/clojure/test/tw/weekly/c129_test.clj b/challenge-129/tyler-wardhaugh/clojure/test/tw/weekly/c129_test.clj
index dbef13c1ec..814efe0998 100644
--- a/challenge-129/tyler-wardhaugh/clojure/test/tw/weekly/c129_test.clj
+++ b/challenge-129/tyler-wardhaugh/clojure/test/tw/weekly/c129_test.clj
@@ -1,7 +1,7 @@
 (ns tw.weekly.c129-test
   (:require [clojure.test :refer [deftest is testing]]
             [tw.weekly.c129.t1 :refer [root-distance]]
-            #_[tw.weekly.c129.t2 :refer []]))
+            [tw.weekly.c129.t2 :refer [add-lists]]))
 
 (def tree-1 '(1 (2) (3 nil (4 (5) (6)))))
 (def tree-2 '(1 (2 (4 nil (6 (8) (9)))) (3 nil (5 (7)))))
@@ -17,4 +17,6 @@
     (is (= 3 (root-distance tree-2 6)))))
 
 (deftest task-2
-  (testing "Task 2, Add Linked Lists"))
+  (testing "Task 2, Add Linked Lists"
+    (is (= '(4 4 4) (add-lists '(1 2 3) '(3 2 1))))
+    (is (= '(1 3 0 0 0) (add-lists '(1 2 3 4 5) '(6 5 5))))))