public static BigInteger Divide(BigInteger dividend, BigInteger divisor)
{
if (divisor.Sign == 0)
{
// math.17=BigInteger divide by zero
throw new ArithmeticException(Messages.math17); //$NON-NLS-1$
}
int divisorSign = divisor.Sign;
if (divisor.IsOne)
{
return((divisor.Sign > 0) ? dividend : -dividend);
}
int thisSign = dividend.Sign;
int thisLen = dividend.numberLength;
int divisorLen = divisor.numberLength;
if (thisLen + divisorLen == 2)
{
long val = (dividend.digits[0] & 0xFFFFFFFFL)
/ (divisor.digits[0] & 0xFFFFFFFFL);
if (thisSign != divisorSign)
{
val = -val;
}
return(BigInteger.FromInt64(val));
}
int cmp = ((thisLen != divisorLen)
? ((thisLen > divisorLen) ? 1 : -1)
: Elementary.CompareArrays(dividend.digits, divisor.digits, thisLen));
if (cmp == BigInteger.EQUALS)
{
return((thisSign == divisorSign) ? BigInteger.One : BigInteger.MinusOne);
}
if (cmp == BigInteger.LESS)
{
return(BigInteger.Zero);
}
int resLength = thisLen - divisorLen + 1;
int[] resDigits = new int[resLength];
int resSign = ((thisSign == divisorSign) ? 1 : -1);
if (divisorLen == 1)
{
Division.DivideArrayByInt(resDigits, dividend.digits, thisLen,
divisor.digits[0]);
}
else
{
Division.Divide(resDigits, resLength, dividend.digits, thisLen,
divisor.digits, divisorLen);
}
BigInteger result = new BigInteger(resSign, resLength, resDigits);
result.CutOffLeadingZeroes();
return(result);
}
/**
* Computes the quotient and the remainder after a division by an {@code int}
* number.
*
* @return an array of the form {@code [quotient, remainder]}.
*/
public 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.FromInt64(quo),
BigInteger.FromInt64(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) */
public 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)(BigMath.Abs(val).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));
}