added scoring project with FP style answer

resources/koans.clj

@@ -209,4 +209,18 @@
                         5
                         :hello
                         (6 :this :are)
-                        ]}]]
+                        ]}]
+ ["21_scoring_project" {"__" [(let [group (group-by identity dic)]
+                                (reduce + (map #(let [coun (count (get % 1))
+                                                      nu (get % 0)]
+                                                  (case nu
+                                                    1 (cond (= coun 3) 1000
+                                                            (< coun 3) (* 100 coun)
+                                                            (> coun 3) (+ 1000 (* 100 (- coun 3))))
+                                                    5 (cond (= coun 3) 500
+                                                            (< coun 3) (* coun 50)
+                                                            (> coun 3) (+ 500 (* (- coun 3) 50)))
+                                                    (if (>= coun 3)
+                                                      (* nu 100)
+                                                      0)))
+                                               group)))]}]]

src/koans/21_scoring_project.clj

@@ -0,0 +1,73 @@
+; Greed is a dice game where you roll up to five dice to accumulate
+; points.  The following "score" function will be used calculate the
+; score of a single roll of the dice.
+;
+; A greed roll is scored as follows:
+;
+; * A set of three ones is 1000 points
+;
+; * A set of three numbers (other than ones) is worth 100 times the
+;   number. (e.g. three fives is 500 points).
+;
+; * A one (that is not part of a set of three) is worth 100 points.
+;
+; * A five (that is not part of a set of three) is worth 50 points.
+;
+; * Everything else is worth 0 points.
+;
+;
+; Examples:
+;
+; (score [1 1 1 5 1]) => 1150 points
+; (score [2 3 4 6 2]) => 0 points
+; (score [3 4 5 3 3]) => 350 points
+; (score [1 5 1 2 4]) => 250 points
+;
+; More scoring examples are given in the tests below:
+;
+; Your goal is to write the score method.
+;
+; It's important to write this method in functional programming
+; style, which is using high-level function instead of using
+; function that has side-effect.
+
+(defn score [dic]
+  __)
+
+(meditations
+  "score of an empty list is zero"
+  (= 0 (score []))
+
+  "score of a single roll of 5 is 50"
+  (= 50 (score [5]))
+
+  "score of a single roll of 1 is 100"
+  (= 100 (score [1]))
+
+  "score of multiple 1s and 5s is the sum of individual scores"
+  (= 300 (score [1 5 5 1]))
+
+  "score of single 2s 3s 4s and 6s are zero"
+  (= 0 (score [2 3 4 6]))
+
+  "score of a triple 1 is 1000"
+  (= 1000 (score [1 1 1]))
+
+  "score of other triples is 100x"
+  (and
+    (= 200 (score [2 2 2]))
+    (= 300 (score [3 3 3]))
+    (= 400 (score [4 4 4]))
+    (= 500 (score [5 5 5]))
+    (= 600 (score [6 6 6])))
+
+  "score of mixed is sum"
+  (and
+    (= 250 (score [2 5 2 2 3]))
+    (= 550 (score [5 5 5 5]))
+    (= 1150 (score [1 1 1 5 1])))
+
+  "ones not left out"
+  (and
+    (= 300 (score [1 2 2 2]))
+    (= 350 (score [1 5 2 2 2]))))