/**
* Computes the quotient and the remainder after a division by an {@code int}
* number.
*
* @return an array of the form {@code [quotient, remainder]}.
*/
internal static BigInteger[] divideAndRemainderByInteger(BigInteger val,
int divisor, int divisorSign)
{
// res[0] is a quotient and res[1] is a remainder:
int[] valDigits = val.digits;
int valLen = val.numberLength;
int valSign = val.sign;
if (valLen == 1)
{
long a = (valDigits[0] & 0xffffffffL);
long b = (divisor & 0xffffffffL);
long quo = a / b;
long rem = a % b;
if (valSign != divisorSign)
{
quo = -quo;
}
if (valSign < 0)
{
rem = -rem;
}
return(new BigInteger[] { BigInteger.ValueOf(quo),
BigInteger.ValueOf(rem) });
}
int quotientLength = valLen;
int quotientSign = ((valSign == divisorSign) ? 1 : -1);
int[] quotientDigits = new int[quotientLength];
int[] remainderDigits;
remainderDigits = new int[] { Division.divideArrayByInt(
quotientDigits, valDigits, valLen, divisor) };
BigInteger result0 = new BigInteger(quotientSign, quotientLength,
quotientDigits);
BigInteger result1 = new BigInteger(valSign, 1, remainderDigits);
result0.CutOffLeadingZeroes();
result1.CutOffLeadingZeroes();
return(new BigInteger[] { result0, result1 });
}
/** @see BigInteger#ToString(int) */
internal static string bigInteger2String(BigInteger val, int radix)
{
int sign = val.sign;
int numberLength = val.numberLength;
int[] digits = val.digits;
if (sign == 0)
{
return("0"); //$NON-NLS-1$
}
if (numberLength == 1)
{
int highDigit = digits[numberLength - 1];
long v = highDigit & 0xFFFFFFFFL;
if (sign < 0)
{
// Long.ToString has different semantic from C# for negative numbers
return("-" + Convert.ToString(v, radix));
}
return(Convert.ToString(v, radix));
}
if ((radix == 10) || (radix < CharHelper.MIN_RADIX) ||
(radix > CharHelper.MAX_RADIX))
{
return(val.ToString());
}
double bitsForRadixDigit;
bitsForRadixDigit = System.Math.Log(radix) / System.Math.Log(2);
int resLengthInChars = (int)(val.Abs().BitLength / bitsForRadixDigit + ((sign < 0) ? 1
: 0)) + 1;
char[] result = new char[resLengthInChars];
int currentChar = resLengthInChars;
int resDigit;
if (radix != 16)
{
int[] temp = new int[numberLength];
Array.Copy(digits, 0, temp, 0, numberLength);
int tempLen = numberLength;
int charsPerInt = digitFitInInt[radix];
int i;
// get the maximal power of radix that fits in int
int bigRadix = bigRadices[radix - 2];
while (true)
{
// divide the array of digits by bigRadix and convert remainders
// to CharHelpers collecting them in the char array
resDigit = Division.divideArrayByInt(temp, temp, tempLen, bigRadix);
int previous = currentChar;
do
{
result[--currentChar] = CharHelper.forDigit(
resDigit % radix, radix);
} while (((resDigit /= radix) != 0) && (currentChar != 0));
int delta = charsPerInt - previous + currentChar;
for (i = 0; i < delta && currentChar > 0; i++)
{
result[--currentChar] = '0';
}
for (i = tempLen - 1; (i > 0) && (temp[i] == 0); i--)
{
;
}
tempLen = i + 1;
if ((tempLen == 1) && (temp[0] == 0)) // the quotient is 0
{
break;
}
}
}
else
{
// radix == 16
for (int i = 0; i < numberLength; i++)
{
for (int j = 0; (j < 8) && (currentChar > 0); j++)
{
resDigit = digits[i] >> (j << 2) & 0xf;
result[--currentChar] = CharHelper.forDigit(resDigit, 16);
}
}
}
while (result[currentChar] == '0')
{
currentChar++;
}
if (sign == -1)
{
result[--currentChar] = '-';
}
return(new String(result, currentChar, resLengthInChars - currentChar));
}
