/********************************** A2R.C ***********************************/
/* Created by: Manuel F Martínez.                          manpaz@email.com */
/* Language:   C/C++                                                        */
/* Date:       Guatemala April 15, 2001                                     */
/* ************************************************************************ */
/* Target: Convert an Arabical numeral to Roman, the input is any value in  */
/*         1 to 3000 range of integers.                                     */
/* Description:  The program take  the input  value and  the value of this  */
/*               position.                                                  */
/*                   e.g.:  int ArabicalNumeral = 3 7 5 9                   */
/* The  number 3 to be in  the first position,  the number 7 in the second, */
/*                the number 5 ...   ;  to obtain the 3 do:                 */
/*                     result = ArabicalNumeral / 1000                      */
/*               Then result store the value of "thousands".                */
/*  After,  the function a2roman ( int, char, char, char ),  receive 1 int  */
/*  parameter and 3 char, the char parameters indicates the three possible  */
/*  roman values to this  number and, the int indicates the value of  this  */
/*  position, the a2roman analizes the number and return a string with the  */
/*  equivalent  roman  number.  After , do  the  same  operation  for  the  */
/*  "hundreds", only that Result is equal to "Arabical % 100" and etc.      */
/****************************************************************************/
/* NOTE:  IF YOU USE VISUAL C++, FIRST CREATE A WORKSPACE, SECOND CLEAR THE */
/*        LINE "clrscr();" THEN COMPILE THE PROGRAM.                        */
/****************************************************************************/
 
/* HEADER FILES */
#include <stdio.h>
#include <conio.h>
#include <string.h>
 
/* The char "c1" and "c2" are initialized in order that not affect the thousands */
char *a2roman (int value, char *c1, char *c2, char *c3);
 
int main (void)
{
	int arabicalNumeral = 1; /* Initialization for read althought one time  */
	int result;              /* "result" store the position value           */
	char roman[15] = "";     /* "roman" contain the roman-numeral string    */
 
	/* This cicle allow to continue if "arabicalNumber" to be in the range */
	do
	{
		/* Clear the screen */
		clrscr();
 
		/* Print a message to user */
		printf ("Enter a integer in 1 to 3000 range of integers: nt");
 
		/* Read the value */
		scanf ("%d", &arabicalNumeral);
	}
	while ((arabicalNumeral < 1) || (arabicalNumeral > 3000));
 
	/* Obtain the value of thousands */
	if ((arabicalNumeral <= 3000) && (arabicalNumeral >= 1000))
	{
		result = arabicalNumeral / 1000;
		strcat (roman, a2roman(result, "M", " ", " "));
		arabicalNumeral -= (result * 1000);
	}
 
	/* Obtain the value of hundreds */
	if ((arabicalNumeral < 1000) && (arabicalNumeral >= 100))
	{
		result = arabicalNumeral / 100;
		strcat (roman, a2roman(result, "C", "D", "M"));
		arabicalNumeral -= (result * 100);
	}
 
	/* Obtain the value of tens */
	if ((arabicalNumeral < 100) && (arabicalNumeral >= 10))
	{
		result = arabicalNumeral / 10;
		strcat (roman, a2roman(result, "X", "L", "C"));
		arabicalNumeral -= (result * 10);
	}
 
	/* Obtain the value of units */
	if ((arabicalNumeral < 10) && (arabicalNumeral >= 1))
	{
		strcat (roman, a2roman(arabicalNumeral, "I", "V", "X"));
	}
 
	/* Display the Roman numeral */
	printf ("The Roman numeral is: nt%snn", roman);
	printf ("tt      ...Press any key to exit.");
	getch();
 
	/* Succesfull return */
	return 0;
}
 
char *a2roman (int value, char *c1, char *c2, char *c3)
{
	int i;	/* "i" is the index of the iteration */
	char rRoman[15] = "";
 
	/* If value = 1, 2, 3 */
	if ((value >= 1) && (value <= 3))
	{
		for (i = 0; i < value; i++)
			strcat (rRoman, c1);
	}
 
	/* If value = 5, 6, 7, 8 */
	if ((value >= 5) && (value <= 8))
	{
		strcat (rRoman, c2);
 
		for (i = 0; i < (value - 5); i++)
			strcat (rRoman, c1);
	}
 
	/* If value = 4 */
	if (value == 4)
	{
		strcat (rRoman, c1);
		strcat (rRoman, c2);
	}
 
	/* If value = 9 */
	if (value == 9)
	{
		strcat (rRoman, c1);
		strcat (rRoman, c3);
	}
 
	return (rRoman);
}