[Linux-disciples] Base 10 to base 26

[Jamie Forrest]

How bout this?

public String decToBase26(int numberToConvert) {
    int x;
    StringBuffer value = "";
    while numberToConvert > 0 {
       x = int(((numberToConvert/26)-int(numberToConvert/26))*27.5)
       value.append(char(x+64));
       numberToConvert = int(numberToConvert/26)
    }
    return value.toString();
}

On Jun 6, 2006, at 11:00 AM, Stephen R Laniel wrote:

> For silly reasons, I need to be able to convert a number to
> a letter -- e.g., 26 = Z, 27 = AA, etc. Is there a quick,
> easy way to do a change of base between base 10 and base 26?
>
> Incidentally, there's a very elegant algorithm to convert
> from base 10 to base 2 in the "Higher-Order Perl" book. All
> integers N are equal to 2k + b, where b is either 0 or 1 and
> k is a smaller integer. To figure out whether b is 0 or 1 in
> the binary expansion of N, just look at whether N is an even
> number or odd. If it's even, then k = 0; if it's odd, k = 1.
> Then divide by 2 to get k. Division by 2 is really easy on
> computers: just bit-shift the number one place to the right.
> Repeat the above steps until k is 0 or 1. The full code
> is below; it could probably be shortened.
>
> But if you can help me convert to base 26, that'd be sweet.
>
> sub decimal_to_binary {
> 	my $inNum = shift;
> 	my $k = 0;
> 	my $b = 0;
> 	if( $inNum == 1 || $inNum == 0 ) {
> 		return $inNum;
> 	}
> 	else {
> 		if( isEven( $inNum ) ) {
> 			$b = 0;
> 		}
> 		else {
> 			$b = 1;
> 		}
> 		$k = ($inNum - $b)/2;
> 		return decimal_to_binary($k) . $b;
> 	}
> }
>
> sub isEven {
> 	return ($_[0] % 2 == 0);
> }
> -- 
> Stephen R. Laniel
> steve at laniels.org
> Cell: +(617) 308-5571
> http://laniels.org/
> PGP key: http://laniels.org/slaniel.key
> _______________________________________________
> Linux-disciples mailing list
> Linux-disciples at lists.bostoncoop.net
> http://lists.bostoncoop.net/mailman/listinfo/linux-disciples

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