示例#1
0
        private static void SingleDivide(BigInteger leftSide, BigInteger rightSide, out BigInteger quotient, out BigInteger remainder)
        {
            if (rightSide.IsZero)
            {
                throw new DivideByZeroException();
            }

            DigitsArray remainderDigits = new DigitsArray(leftSide.m_digits);
            remainderDigits.ResetDataUsed();

            int pos = remainderDigits.DataUsed - 1;
            ulong divisor = (ulong)rightSide.m_digits[0];
            ulong dividend = (ulong)remainderDigits[pos];

            DType[] result = new DType[leftSide.m_digits.Count];
            leftSide.m_digits.CopyTo(result, 0, result.Length);
            int resultPos = 0;

            if (dividend >= divisor)
            {
                result[resultPos++] = (DType)(dividend / divisor);
                remainderDigits[pos] = (DType)(dividend % divisor);
            }
            pos--;

            while (pos >= 0)
            {
                dividend = ((ulong)(remainderDigits[pos + 1]) << DigitsArray.DataSizeBits) + (ulong)remainderDigits[pos];
                result[resultPos++] = (DType)(dividend / divisor);
                remainderDigits[pos + 1] = 0;
                remainderDigits[pos--] = (DType)(dividend % divisor);
            }
            remainder = new BigInteger(remainderDigits);

            DigitsArray quotientDigits = new DigitsArray(resultPos + 1, resultPos);
            int j = 0;
            for (int i = quotientDigits.DataUsed - 1; i >= 0; i--, j++)
            {
                quotientDigits[j] = result[i];
            }
            quotient = new BigInteger(quotientDigits);
        }
示例#2
0
        private void ConstructFrom(byte[] array, int offset, int length)
        {
            if (array == null)
            {
                throw new ArgumentNullException("array");
            }
            if (offset > array.Length || length > array.Length)
            {
                throw new ArgumentOutOfRangeException("offset");
            }
            if (length > array.Length || (offset + length) > array.Length)
            {
                throw new ArgumentOutOfRangeException("length");
            }

            int estSize = length / 4;
            int leftOver = length & 3;
            if (leftOver != 0)
            {
                ++estSize;
            }

            m_digits = new DigitsArray(estSize + 1, 0); // alloc one extra since we can't init -'s from here.

            for (int i = offset + length - 1, j = 0; (i - offset) >= 3; i -= 4, j++)
            {
                m_digits[j] = (DType)((array[i - 3] << 24) + (array[i - 2] << 16) + (array[i - 1] << 8) + array[i]);
                m_digits.DataUsed++;
            }

            DType accumulator = 0;
            for (int i = leftOver; i > 0; i--)
            {
                DType digit = array[offset + leftOver - i];
                digit = (digit << ((i - 1) * 8));
                accumulator |= digit;
            }
            m_digits[m_digits.DataUsed] = accumulator;

            m_digits.ResetDataUsed();
        }
示例#3
0
 /// <summary>
 /// Copy constructor, doesn't copy the digits parameter, assumes <code>this</code> owns the DigitsArray.
 /// </summary>
 /// <remarks>The <paramef name="digits" /> parameter is saved and reset.</remarks>
 /// <param name="digits"></param>
 private BigInteger(DigitsArray digits)
 {
     digits.ResetDataUsed();
     this.m_digits = digits;
 }
示例#4
0
 /// <summary>
 /// Creates a BigInteger with the value of the operand. Can never be negative.
 /// </summary>
 /// <param name="number">A unsigned long.</param>
 public BigInteger(ulong number)
 {
     m_digits = new DigitsArray((8 / DigitsArray.DataSizeOf) + 1, 0);
     while (number != 0 && m_digits.DataUsed < m_digits.Count)
     {
         m_digits[m_digits.DataUsed] = (DType)(number & DigitsArray.AllBits);
         number >>= DigitsArray.DataSizeBits;
         m_digits.DataUsed++;
     }
     m_digits.ResetDataUsed();
 }