Data commit

Task/Sorting-algorithms-Strand-sort/Clojure/sorting-algorithms-strand-sort.clj

@@ -0,0 +1,35 @@
+(ns rosettacode.strand-sort)
+
+(defn merge-join
+  "Produces a globally sorted seq from two sorted seqables"
+  [[a & la :as all] [b & lb :as bll]]
+  (cond (nil? a) bll
+        (nil? b) all
+        (< a b) (cons a (lazy-seq (merge-join la bll)))
+        true    (cons b (lazy-seq (merge-join all lb)))))
+
+(defn unbraid
+  "Separates a sorted list from a sequence"
+  [u]
+  (when (seq u)
+    (loop [[x & xs] u
+           u []
+           s []
+           e x]
+      (if (nil? x)
+        [s u]
+        (if (>= x e)
+          (recur xs u (conj s x) x)
+          (recur xs (conj u x) s e))))))
+
+(defn strand-sort
+  "http://en.wikipedia.org/wiki/Strand_sort"
+  [s]
+  (loop [[s u] (unbraid s)
+         m nil]
+    (if s
+      (recur (unbraid u) (merge-join m s))
+      m)))
+
+(strand-sort [1, 6, 3, 2, 1, 7, 5, 3])
+;;=> (1 1 2 3 3 5 6 7)