C++ Roman Numeral Converter

ACSUSA · 01-12-2011, 07:34 PM

I am trying to finish up my intro C++ course, and have to make a Roman numeral to Arabic converter. I had no trouble with the reverse (Arabic to Roman), but I must be missing something on this one. I tried a few variations, and either got 0 or an insanely high number as the output.

Code:

#include<iostream>
#include<cstring>

using namespace std;



int main() {

    char roman[20];

    int arabic, x, y;

    cout << "Roman Numeral to Arabic Number Converter" << endl;

    cout << "Please enter a Roman Numeral to convert: ";

    cin.get(roman, 20);

    cin.ignore(80, '\n');

    

    x = strlen(roman);

    

    for(y = 1;y == x; y++) {

    	if(roman[y] == 'M') {

    		arabic = arabic + 1000;

    	}

    	if(roman[y] == 'D') {

    		arabic = arabic + 500;

    	}

    	if(roman[y] == 'C') {

    		arabic = arabic + 100;

    	}

    	if(roman[y] == 'L') {

    		arabic = arabic + 50;

    	}

    	if(roman[y] == 'X') {

    		arabic = arabic + 10;

    	}

    	if(roman[y] == 'V') {

    		arabic = arabic + 5;

    	}

    	if(roman[y] == 'I') {

    		arabic = arabic + 1;

    	}

    }

    

    cout << "You entered " << x << " character(s)." << endl;
    cout << "Your arabic number is: " << arabic << endl;

    

    return 0;

}

dwhitney67 · 01-12-2011, 08:50 PM

Here's a hint... initialize the variable 'arabic'.

Another... fix the for-loop's initial state and conditional statement.

Also, "IV" is 4, not 6 as your program will compute. It would seem that you have more work ahead.

moneya · 02-24-2011, 09:11 AM

Quote:

I am trying to finish up my intro C++ course, and have to make a Roman numeral to Arabic converter. I had no trouble with the reverse (Arabic to Roman), but I must be missing something on this one. I tried a few variations, and either got 0 or an insanely high number as the output.

LOL i found this thread in a search i did trying to find the answer to the same question, as i have intro to C++ as an online class thanks!

dwhitney67 · 02-24-2011, 09:35 AM

Quote:

Originally Posted by moneya

LOL i found this thread in a search i did trying to find the answer to the same question, as i have intro to C++ as an online class thanks!

I think that the point of your exercise is to employ the use of independent thought versus trying to locate an answer on the web.

We've all heard the argument against "reinventing the wheel", however that notion surely does not apply to students.