:
:
:
:
switch(character){
case 'M':
cout<<sum += 1000;

break;
case 'D':

cout<<sum sum += 500;
:
:
:
:
:
case 'I':
cout<< sum += 1;
break;

}
This is the basic for for coverting Roman figures to decimal base 10. When I try VII I get same respond as IIV that is 7 or IX and XI as 11 whereas, IIV does not exist, neither is IX = 11. Any help? Test with an input such as MIX or IVC to be 1009 and 96 respectively. Urgent!! Email: smart_ikhu@hotmail.com
Thanks.

Can you provide your full code? What is your intent with this line?

That line was just a typo error. It is like others cout<<sum += 500;

I want to manipulate all the possibilities with Roman to Base 10 numbers. Examples, VI = 6 and IV = 4. With the above selection code, I get IV = VI or IX = XI. I want to make sure, I can have MIV = 1004 and not 1006 or IXM = 991 and not 1011.
Thanks. I am online waiting for your help.


The complete code is

while((c = fgetc(stdin)) != '\n'){

switch©{

case 'M':
sum += 1000;
printf("%d", sum);
break;

case 'M':
sum += 1000;
printf("%d", sum);
break;


case 'M':
sum += 1000;
printf("%d", sum);
break;

case 'D':
sum += 500;
printf("%d", sum);
break;


:
:
:
case 'V':
sum += 5;
printf("%d", sum);
break;
case 'I':
sum += 1;
printf("%d", sum);
break;

default:
break;

}

}


Please, I want IX = 11, and IX = 9.
Thanks.
SmartC

The problem is that you are making your decisions based on one character at a time. There are situations in which you will have to check the NEXT character before making a decision on what to do with the previous character. the character following the original character will drive the decision, not the original character.

So, how do I input next character? I need this help. Your idea sounds to be on track.
Thanks

First, I'd ask what language you are using...your first code appears to be C++, the second is C. If you are using C++, I suggest getting the entire input as one string object and parsing it, or id C, a character array.

I want to use both languages to test my program. C appears to be more appealling for now. I will like to test it in C first.
Please, help in the C. C++ is not appealling in this case.
Thanks.
SmartC.

Not sure what you mean by appealing, but it could be accomplished in C++ much easier.

c it is...

Can you modify your program to take the user input as a single string (character array)?

That is like char array1[3] = "IV"; char array2[3] = "IX"; char array3[3] = "XL"; etc, for the special cases, but when I thought along this line, it is another up hill task since so many variables will be involved. I beleive that your idea is radiating a possible solution. Specifically, I am using C. Thanks thus far.
SmartC.

I was thinking more along the lines of:

You now have the roman numeral in a single character array, and can check any of the characters, including the next one.

Ok,
I have this codes, but it is in the reverse. From Decimal to Roman. Could you be kind enough to make it perform the other way round. From Roman to decimal? I will be glad you do. Thanks.
smartC

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>



unsigned int roman_ranges[] = { 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4,

1, 0 };
unsigned int roman_addsin[] = {-1000, +100, -500, +100, -100, +10, -50, +10, -10, +1, -5, +1,

-1, 0 };
char roman_letters[] = { 'M', 'C', 'D', 'C', 'C', 'X', 'L', 'X', 'X', 'I', 'V', 'I',

'I', 0 };

size_t find_index(unsigned int li) {
unsigned int *roman_ranges_ptr = roman_ranges;
while (*roman_ranges_ptr && li < *roman_ranges_ptr) {
++roman_ranges_ptr;
}
return roman_ranges_ptr - roman_ranges;
}



char* de2roman(char* buf, unsigned int li, size_t bufsize) {
size_t index;
if (bufsize < 1) {
return NULL; // buffer size is not enough for convertion
}
if ( (*buf = roman_letters[ (index = find_index(li)) ]) ) {
return de2roman(buf+1, li + roman_addsin[index], bufsize-1);
}
return buf;
}

#define ROMAN_NUMBER_BUF_SIZE 64

int main() {
unsigned int nr;
char roman_str[ROMAN_NUMBER_BUF_SIZE];

/* printf("%s", "Enter an integer: ");
scanf("%s", roman_str);*/
// while((nr = fgetc(stdin)) != '\n'){


while((scanf("%s", roman_str)) != '\n'){

de2roman(roman_str, nr, ROMAN_NUMBER_BUF_SIZE);
printf(" %d\n", nr);

}
return 0;
}

This post has been edited by smartC: 28 Jul, 2007 - 02:16 AM

you already have the solution in the code above, try to think this through.