Month

Brief Information about the Dec '02 CSIG Meetings

ROMAN - A Text Based Utility for Roman Numerals

The subject for this month is a program to convert Arabic numbers into Roman numerals. These numbers appear often in our society: on buildings, in books, on statues, etc. They are often used where a date is to be represented in a fashion that will last for hundreds of years. Have you ever thought how you might "teach" a computer to print out the year, or any year, in Roman numerals?

The program consists of a number of parts. The basic program is a text mode 32-bit application that runs in a "Command Box" (sometimes called a DOS box). As such, it is generally computer and compiler independent. I will be using the Microsoft C++ compiler but it should run on GNU or other compilers. When the program starts it announces itself and asks for a number. It then uses several routines to convert the number into Roman. For example, if you enter 1957, it prints out MCMLVII.

Sample Code

int main(int argc, char* argv[])
    {
    char buff[50];
    unsigned int n ;       /* Number to be converted */
    int code;

    printf("\n\n ROMAN NUMERAL CONVERSION UTILITY  ( end = 0 )\n");
    do
      {
      printf("\n Enter a number, 0..65535 : ");
      fgets(buff,50,stdin);
         code=sscanf(buff,"%5u",&n);
      if (code != 1) continue;   /* go to top of loop   */
      
      result[0] = 0;       /* erase previous result  */
      convert(n);
      printf(  "%5u -----------------------------> %s\n",n,result);

      if(n > 3999) 
         printf("( Special characters:  * 5000, # 10000, @ 50000 )\n");
      }
    while (n > 0);
   return 0;
    }

void convert(unsigned int n)     /* Convert the number to R.N. */
   {                             /* NON-Recursive version   */
   char buff[20];
   int i, len;
   sprintf(buff,"%u",n);
   len = strlen(buff);
   for (i=0; i < len; i++)
       {
       tentimes();            /* Multiply result string by 10  */
       roman(buff[i] - '0');  /* fill 'result' buffer    */
       }
   }

void convert2(unsigned int n)    /* Convert the number to R.N. */
   {                             /* Recursive version    */
   if (n/10 != 0)
      {
      convert2(n / 10);    /* R e c u r s i v e    c a l l */
      tentimes();          /* Multiply result string by 10  */
      }
   roman(n % 10);          /* Convert this one digit  */
   }

SOURCE CODE

Source Code Files