1. write a C program to convert a Roman numeral to its decimal equivalent.

 program:

 #include <stdio.h>

#include <conio.h>

#include <string.h>

#include <stdlib.h>

void main()

{

 char rom[30];

 int a[30], l, i, k, dec;

 clrscr();

 printf("Enter the roman number\n");

 scanf("%s", &rom);

 l =strlen(rom);

 for(i = 0; i < l; i++)

 {

 switch (rom[i])

 {

 case 'I': a[i] = 1;

 break;

 case 'V': a[i] = 5;

 break;

 case 'X': a[i] = 10;

 break;

 case 'L': a[i] = 50;

 break;

 case 'C': a[i] = 100;

 break;

 case 'D': dec = dec + 500;

 break;

 case 'M': a[i] = 1000;

 break;

 default : printf("Invalid choice");

 break;

 }

 }

 k = a[l - 1];

 for(i = l - 1; i > 0; i--)

 {

 if(a[i] > a[i - 1])

 {

 k = k - a[i - 1];

 }

 if(a[i] <= a[i - 1])

 {

 k = k + a[i - 1];

 }

 }

 printf("decimal equivalent is %d", k);

 getch();

}

output: