update

Task/Sorting-algorithms-Strand-sort/Racket/sorting-algorithms-strand-sort.rkt

@@ -0,0 +1,17 @@
+#lang racket
+(require mzlib/list)
+(define (merge xs ys) (merge-sorted-lists xs ys <=))
+
+(define (strand-sort xs)
+  (let loop ([xs xs] [ys '[]])
+    (cond [(empty? xs) ys]
+          [else (define-values (sorted unsorted) (extract-strand xs))
+                (loop unsorted (merge sorted ys))])))
+
+(define (extract-strand xs)
+  (for/fold ([strand '()] [unsorted '[]]) ([x xs])
+    (if (or (empty? strand) (< x (first strand)))
+        (values (cons x strand) unsorted)
+        (values strand (cons x unsorted)))))
+
+(strand-sort (build-list 10 (λ(_) (random 15))))