try this function i made ...simplest possible... so far wherever i tried it worked... if there's any mistake please be sure to tell me...
Code:
int RomanTodecimal(String roman)
    {
        int l= roman.length();
        int i;
        int deci=0;
        int num=0;
        for (i=l-1;i>=0;i--)
        { char x = roman.charAt(i);
            x = Character.toUpperCase(x);
...