Initial data commit

Task/Gray-code/Racket/gray-code.rkt

@@ -0,0 +1,18 @@
+#lang racket
+
+(define (gray-encode n) (bitwise-xor n (arithmetic-shift n -1)))
+
+(define (gray-decode n)
+  (letrec ([loop (lambda(g bits)
+                   (if (> bits 0)
+                       (loop (bitwise-xor g bits) (arithmetic-shift bits -1))
+                       g))])
+	 (loop 0 n)))
+
+(define (to-bin n) (format "~b" n))
+(define (show-table)
+  (for ([i (in-range 1 32)])
+    (printf "~a | ~a | ~a ~n"
+            (~r i #:min-width 2 #:pad-string "0")
+            (~a (to-bin(gray-encode i)) #:width 5 #:align 'right #:pad-string "0")
+            (~a (to-bin (gray-decode(gray-encode i))) #:width 5 #:align 'right #:pad-string "0"))))