Roman Numerals --> Integers

[tim_l_012]

HI, I need someone to give me code for this in VB, and in c++..

I need a program the will convert a roman numeral into an integer...

Thanks,

ps: remember, vb and c++, cheers.

[Matthew Gates]

The file attached should help you with what your after.

[da_silvy]

Here is some code i wrote (translated)

Private Sub Form_Load()
MsgBox RomanToDecimal("CCCLXIX")
End Sub
Function RomanToDecimal(Roman As String) As String
Dim conv(7) As Variant
Dim arabic As Integer, state As Integer, length As Integer, i As Integer, sidx As Integer
conv(0) = "I,1"
conv(1) = "V,5"
conv(2) = "X,10"
conv(3) = "L,50"
conv(4) = "C,100"
conv(5) = "D,500"
conv(6) = "M,1000"
conv(7) = "0,0"
length = Len(Roman)
state = 0
Do While length >= 0
          i = 0
            sidx = length
            romnumber = CInt(Mid(conv(i), InStr(1, conv(i), ",") + 1, Len(conv(i)) - InStr(1, conv(i), ",")))
            Do While romnumber > 0
            comp1 = (Right(Left(Roman, sidx), 1))
                comp2 = Left(conv(i), 1)
                If (LCase(comp1)) = CStr(LCase(comp2)) Then
                    If state > romnumber Then
                        arabic = arabic - romnumber
                    Else
                        arabic = arabic + romnumber
                        state = romnumber
                    End If
                    End If
                        i = i + 1
            
            If i = 8 Then GoTo ending:
                        romnumber = CInt(Mid(conv(i), InStr(1, conv(i), ",") + 1, Len(conv(i)) - InStr(1, conv(i), ",")))
            Loop
            length = length - 1
Loop
ending:
RomanToDecimal = arabic
           
           
End Function

Also - I can't do this in C++
Here was the base code, for anyone who doesn't understand mine:

    function toNumber($roman)
    {
        $conv = array(
            array("letter" => 'I', "number" => 1),
            array("letter" => 'V', "number" => 5),
            array("letter" => 'X', "number" => 10),
            array("letter" => 'L', "number" => 50),
            array("letter" => 'C', "number" => 100),
            array("letter" => 'D', "number" => 500),
            array("letter" => 'M', "number" => 1000),
            array("letter" => 0,   "number" => 0)
        );
        $arabic = 0;
        $state  = 0;
        $sidx   = 0;
        $len    = strlen($roman);
    
        while ($len >= 0) {
            $i = 0;
            $sidx = $len;
            
            while ($conv[$i]['number'] > 0) {
                if (strtoupper($roman[$sidx]) == $conv[$i]['letter']) {
                    if ($state > $conv[$i]['number']) {
                        $arabic -= $conv[$i]['number'];
                    } else {
                        $arabic += $conv[$i]['number'];
                        $state   = $conv[$i]['number'];
                    }
                }
                $i++;
            }

            $len--;
        }
    
        return($arabic);
    }

    // }}}
    // {{{ toRoman()
    
    /**
     * Converts a number to its roman numeral representation
     *
     * @param  integer $num   An integer between 0 and 3999 inclusive
     *                        that should be converted to a roman numeral
     *
     * @return string  $roman The corresponding roman numeral
     *
     * @access public
     * @author Sterling Hughes <[email protected]>
     * @since  PHP 4.0.5
     */
    function toRoman($num) {
        $conv = array(10 => array('X', 'C', 'M'),
                      5  => array('V', 'L', 'D'),
                      1  => array('I', 'X', 'C'));
        $roman = '';
        
        $num = (int) $num;

        $digit  = (int) $num / 1000;
        $num   -= $digit * 1000;
        while ($digit > 0) {
            $roman .= 'M';
            $digit--;
        }

        for ($i = 2; $i >= 0; $i--) {
            $power = pow(10, $i);
            $digit = (int) $num / $power;
            $num -= $digit * $power;

            if (($digit == 9) || ($digit == 4)) {
                $roman .= $conv[1][$i] . $conv[$digit+1][$i];
            } else {
                if ($digit >= 5) {
                    $roman .= $conv[5][$i];
                    $digit -= 5;
                }

                while ($digit > 0) {
                    $roman .= $conv[1][$i];
                    $digit--;
                }
        }

        if ($num > 0) {
            return('');
        }

        return($roman);
    }
    
    // }}}
} 

[plenderj]

As we're all throwing in examples in different languages, heres the src to a converter I had to do in college last year :

... pity its the wrong way around though

public class convert
{
	public static void main (String[] args)
	{		

		int userInput;
		System.out.print("Please enter a number to convert : ");
                userInput = TextIO.getInt();
		if ((userInput > 3999) || (userInput < 0))
		{
			System.out.println("Can only convert numbers between 0 and 3999");
		}
		if ((Integer.toString(userInput).length() > 0) && (Integer.toString(userInput).length() < 5))
		{
			System.out.println(converter(userInput));
		}

	}
	
	public static String converter(int int_number) {
		String to_return = "";
		if (Integer.toString(int_number).length() == 1)
		{
			to_return = onesToRomanNumerals(int_number);
		}
		else if (Integer.toString(int_number).length() == 2) 
		{
			to_return = tensToRomanNumerals(int_number);
		}
		else if (Integer.toString(int_number).length() == 3)
		{	
			to_return = hunsToRomanNumerals(int_number);
		}
		else if (Integer.toString(int_number).length() == 4)
		{
			to_return = thousandsToRomanNumerals(int_number);
		}

		return to_return;
	}
	
	public static String thousandsToRomanNumerals(int int_number) {
		String var_temp = Integer.toString(int_number);
		String var_huns = var_temp.substring(var_temp.length() - 3);
		String var_thou = var_temp.substring(var_temp.length() - 4, var_temp.length() - 3);
		String to_return = "";

		switch (Integer.parseInt(var_thou)) {
			case 0:   to_return = hunsToRomanNumerals(Integer.parseInt(var_huns));
				  break;
			case 1:   to_return = "M" + hunsToRomanNumerals(Integer.parseInt(var_huns));
				  break;
			case 2:   to_return = "MM" + hunsToRomanNumerals(Integer.parseInt(var_huns));
				  break;
			case 3:   to_return = "MMM" + hunsToRomanNumerals(Integer.parseInt(var_huns));
				  break;
		}
		return to_return;
	}
	public static String hunsToRomanNumerals(int int_number) {
		String var_temp = Integer.toString(int_number);
		String var_tens = "", var_huns = "";
		if (Integer.toString(int_number).length() == 3)
		{	
			var_tens = var_temp.substring(var_temp.length() - 2);
			var_huns = var_temp.substring(var_temp.length() - 3, var_temp.length() - 2);
		}
		else if (Integer.toString(int_number).length() == 2)
		{	
			var_tens = var_temp.substring(var_temp.length() - 2);
			var_huns = "0";
		}
		else if (Integer.toString(int_number).length() == 1)
		{	
			var_tens = "0";
			var_huns = "0";
		}
		String to_return = "";

		switch (Integer.parseInt(var_huns)) {
			case 0:   to_return = tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 1:   to_return = "C"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 2:   to_return = "CC"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 3:   to_return = "CCC"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 4:   to_return = "CD"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 5:   to_return = "D"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 6:   to_return = "DC"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 7:   to_return = "DCC"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 8:   to_return = "DCCC"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
			case 9:   to_return = "CM"  + tensToRomanNumerals(Integer.parseInt(var_tens));
				  break;
		}
		return to_return;
	}

	public static String tensToRomanNumerals(int int_number) {
		
		String var_temp = Integer.toString(int_number);
		String var_ones = "", var_tens = "";
		if (Integer.toString(int_number).length() == 1)
		{
			var_ones = Integer.toString(int_number);
			var_tens = "0";
		}
		else if (Integer.toString(int_number).length() == 2)
		{
			var_ones = var_temp.substring(var_temp.length() - 1);
			var_tens = var_temp.substring(var_temp.length() - 2, var_temp.length() - 1);
		}

		String to_return = "";

		switch (Integer.parseInt(var_tens)) {
			case 0:   to_return = onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 1:   to_return = "X"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 2:   to_return = "XX"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 3:   to_return = "XXX"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 4:   to_return = "XL"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 5:   to_return = "L"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 6:   to_return = "LX"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 7:   to_return = "LXX"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 8:   to_return = "LXXX"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
			case 9:   to_return = "XC"  + onesToRomanNumerals(Integer.parseInt(var_ones));
				  break;
		}
		
		
		return to_return;

	}

	public static String onesToRomanNumerals(int int_number) {
		String var_ones = Integer.toString(int_number);
		var_ones = var_ones.substring(var_ones.length() - 1 );
		String to_return = "";

		switch (Integer.parseInt(var_ones)) {
			case 0: to_return = "";
				break;
			case 1: to_return = "I";
				break;
			case 2: to_return = "II";
				break;
			case 3: to_return = "III";
				break;
			case 4: to_return = "IV";
				break;
			case 5: to_return = "V";
				break;
			case 6: to_return = "VI";
				break;
			case 7: to_return = "VII";
				break;
			case 8: to_return = "VIII";
				break;
			case 9: to_return = "IX";
				break;
		}

		return to_return;
	}


}

[da_silvy]

Lol at least I converted it to VB

j/k

[plenderj]

Not just that but at least yours converted the right way around

[da_silvy]

thanks man

i just hope someone else (Parksie maybe? ) can convert my example into C++

[beachbum]

How do you handle the bar above M etc?

[plenderj]

The bar above M ?
What ?

[beachbum]

A bar on top multiplies by one thousand. eg M with bar on top is 1 million. I am not sure of all letters that allow bar on top.
Regards
Stuart

[plenderj]

Eh I only thought the bar was a graphical thing.
Like you can draw I, II, III, IV, VI, VII, VIII and what not with a bar across the top to make it look nice

[c@lle]

a very easy way is to use the function from excel

create a document with in cell b1 the function '=roman(a1)'
save this doc in 'c:\temp' with the name 'roman.xls'

then use this code

 Dim objExcel As Excel.Application
 Dim objWorksheet As Excel.Worksheet
 
 Set objExcel = New Application
 objExcel.Visible = False
 objExcel.Workbooks.Open "c:\temp\roman.xls"
 
 Set objWorksheet = objExcel.ActiveSheet
 
 objWorksheet.Range("a1").Value = Text1.Text
 
 Text2.Text = objWorksheet.Range("b1").Value
 
 objExcel.Workbooks(1).Close (False)
 Set objWorksheet = Nothing
 objExcel.Quit
 Set objExcel = Nothing

[da_silvy]

Yes, yes.

plenderj, we have made more posts on this thread than the owner

I went to your website, yes it is short, but i like the picture

[plenderj]

Its short, but its fat !
You scroll across you see. I though there was lots of interesting info there.

[da_silvy]

AHHH...

I didn't know to scroll across...

That brings new light to your site

[plenderj]

duh

[da_silvy]