Initial data commit

Task/Sorting-algorithms-Shell-sort/Racket/sorting-algorithms-shell-sort.rkt

@@ -0,0 +1,14 @@
+#lang racket
+(define (shell-sort! xs)
+  (define ref (curry vector-ref xs))
+  (define (new Δ) (if (= Δ 2) 1 (quotient (* Δ 5) 11)))
+  (let loop ([Δ (quotient (vector-length xs) 2)])
+    (unless (= Δ 0)
+      (for ([xᵢ (in-vector xs)] [i (in-naturals)])
+        (let while ([i i])
+          (cond [(and (>= i Δ) (> (ref (- i Δ)) xᵢ))
+                 (vector-set! xs i (ref (- i Δ)))
+                 (while (- i Δ))]
+                [else (vector-set! xs i xᵢ)])))
+      (loop (new Δ))))
+  xs)