dtoa

dtoa.java

private static String ltoa(long l, int bas) {
	bool sign = l < 0;
	if (sign) {
		l = -l;
	}

	int digits;
	int neg = 1;
	for (digits = 0; l >= neg; ++digits) {
		neg *= bas;
	}

	char[] chars = new char[digits + (sign ? 1 : 0)];
	for (; digits > 0; --digits) {
		byte b = l % bas;
		l /= bas;
		if (b >= bas) {
			b = 'a' + b;
		} else {
			b = '0' + b;
		}
		chars[digits - (sign ? 0 : 1)] = b;
	}
	if (sign) {
		chars[0] = '-';
	}

	return new String(chars);
}

private static String dtoa(double d, int base) {
	long id = (long)d;
	String b4c = ltoa(id, base);

	d -= id;
	while ((d - (long)d) != 0.0) {
		d *= base;
	}

	id = (long)d;
	String ac = ltoa(id, base);
	return b4c + '.' + ac;
}