View difference between Paste ID: dewmJL50 and X1YVJjaB

 ;; -*- coding: utf-8; mode: scheme -*-
-;; num-roman.rkt
+;; $Id: num-roman.rkt,v 1.6 2012/02/04 21:44:33 alcides_fp Exp $
 #lang racket
 
 (provide numeral)
 
 (define (numeral digito posicion)
   (let ((matriz-numerales
          #(#("" "I" "II" "III" "IV" "V" "VI" "VII" "VIII" "IX")
            #("" "X" "XX" "XXX" "XL" "L" "LX" "LXX" "LXXX" "XC")
            #("" "C" "CC" "CCC" "CD" "D" "DC" "DCC" "DCCC" "CM")
            #("" "M" "MM" "MMM"))))
     (vector-ref (vector-ref matriz-numerales posicion) digito) ))
 ;;------------------------------------------------------------------------
 (provide dec->list)
 
 (define (dec->list numero)
   (let ((retval '())
-        (cadena-num '())
+        (base 10)
         (residuo 0))
     (do ((cantidad numero)) ((= cantidad 0) retval)
       (set! residuo (remainder cantidad base))
-    (set! cadena-num (reverse (string->list (number->string arabigo))))
+      (set! retval (append retval (list residuo) ))
-    (set! longitud (length cadena-num))
+      (set! cantidad (quotient cantidad base)) ) ) )
 ;;------------------------------------------------------------------------
 (provide num-roman)
-         (set! digito (- (char->integer (list-ref cadena-num posicion)) 48))
+
 (define (num-roman arabigo)
   (let ((retval "")
-    retval ))
+        (lista-cifras '())
         (longitud 0)
         (digito 0))
 
     (set! lista-cifras (dec->list arabigo))
     (set! longitud (length lista-cifras))
 
     (for ((posicion longitud))
          (set! digito (list-ref lista-cifras posicion))
          (set! retval (string-append (numeral digito posicion) retval)) )
 
     retval ))
 ;;------------------------------------------------------------------------