Initial data commit

Task/Semordnilap/Racket/semordnilap.rkt

@@ -0,0 +1,14 @@
+#lang racket
+(define seen (make-hash))
+(define semordnilaps '())
+(call-with-input-file "/usr/share/dict/words"
+  (λ(i) (for ([l (in-lines i)])
+          (define r (list->string (reverse (string->list l))))
+          (unless (equal? r l)
+            (hash-set! seen l #t)
+            (when (hash-ref seen r #f)
+              (set! semordnilaps (cons (list r l) semordnilaps)))))))
+(printf "Total semordnilaps found: ~s\n" (length semordnilaps))
+(printf "The five longest ones:\n")
+(for ([s (take (sort semordnilaps > #:key (compose1 string-length car)) 5)])
+  (apply printf "  ~s ~s\n" s))