Question

*MUST BE IN C PROGRAMMING*

• Demonstrate the ability to think critically
• Demonstrate the ability to work with strings and chars
• Demonstrate the ability to design a menu system

Write a simple program that allows the user to enter a number between 1 and 1000.  The program will then display the Roman numeral equivalent.  Allow the user to keep entering numbers for conversion to Roman numerals, or to quit, using a menu system of your own design.

Submission Requirements:

You are to write a good solution - as short, concise, and clever as possible.

Answer 1

#include <stdio.h>

/* Global data to store roman values */
char roman_data[1000];
int i = 0;

void pre(char n1, char n2)
{
roman_data[i++] = n1;
roman_data[i++] = n2;
}

void post(char data, int num)
{
int j;
for (j = 0; j < num; j++) {
roman_data[i++] = data;
}
}

char *roman(long int data)
{
int j;
long int num;
  
num = data;

if (num <= 0 || num > 1000) {
return NULL;
}
/* repeat the loop until num becoms zero */

while (num != 0) {
if (num >= 1000) {
   /* num greater than 1000 */

post('M', num / 1000);
num = num - (num / 1000) * 1000;
} else if (num >= 500) {
   /* num greater than 500 */

if (num < (500 + 4 * 100)) {
post('D', num / 500);
num = num - (num / 500) * 500;
} else {
pre('C','M');
num = num - (1000-100);
}
} else if (num >= 100) {
/* num greater than 100 */

if (num < (100 + 3 * 100)) {
post('C', num / 100);
num = num - (num / 100) * 100;
} else {
pre('L', 'D');
num = num - (500 - 100);
}
} else if (num >= 50 ) {
   /* num greater than 50 */  

if (num < (50 + 4 * 10)) {
post('L', num / 50);
num = num - (num / 50) * 50;
} else {
pre('X','C');
num = num - (100-10);
}
} else if (num >= 10) {
   /* num greater than 10 */

if (num < (10 + 3 * 10)) {
post('X', num / 10);
num = num - (num / 10) * 10;
} else {
pre('X','L');
num = num - (50 - 10);
}
} else if (num >= 5) {
   /* num greater than 5 */

if (num < (5 + 4 * 1)) {
post('V', num / 5);
num = num - (num / 5) * 5;
} else {
pre('I', 'X');
num = num - (10 - 1);
}
} else if (num >= 1) {
   /* num greater than 1 */

if (num < 4) {
post('I', num / 1);
num = num - (num / 1) * 1;
} else {
pre('I', 'V');
num = num - (5 - 1);
}
}
}

roman_data[i]='\0'; /* Add null character at end of the string */
return(roman_data);
}

int main()
{
   int long val;
   char *ptr;
   char choice;

   while(1){

   printf("Enter the number to convert into Roman: Or -1 to Quit\n");
   scanf("%ld",&val);

if(val == -1){
break;
}
   ptr = roman(val);
   if(ptr == NULL){
       printf("NUmber Not in the range\n");
   }else{
       printf("Roman number is: %s\n",ptr);
   }
roman_data[0]='\0';
i = 0;
   }

return 0;
}