| public static DivMod ( uint digits1, uint length1, uint int2, uint divRes, uint &modRes ) : uint | ||
| digits1 | uint | First big integer digits. |
| length1 | uint | First big integer length. |
| int2 | uint | Second integer. |
| divRes | uint | Div result (can be null - not filled in this case). |
| modRes | uint | Remainder (always filled). |
| return | uint | |
/// <summary>
/// Converts digits from internal representaion into given base.
/// </summary>
/// <param name="digits">Big integer digits.</param>
/// <param name="length">Big integer length.</param>
/// <param name="numberBase">Base to use for output.</param>
/// <param name="outputLength">Calculated output length (will be corrected inside).</param>
/// <returns>Conversion result (later will be transformed to string).</returns>
override public uint[] ToString(uint[] digits, uint length, uint numberBase, ref uint outputLength)
{
uint[] outputArray = base.ToString(digits, length, numberBase, ref outputLength);
// Maybe base method already converted this number
if (outputArray != null)
{
return(outputArray);
}
// Create an output array for storing of number in other base
outputArray = new uint[outputLength + 1];
// Make a copy of initial data
uint[] digitsCopy = new uint[length];
Array.Copy(digits, digitsCopy, length);
// Calculate output numbers by dividing
uint outputIndex;
for (outputIndex = 0; length > 0; ++outputIndex)
{
length = DigitOpHelper.DivMod(digitsCopy, length, numberBase, digitsCopy, out outputArray[outputIndex]);
}
outputLength = outputIndex;
return(outputArray);
}
/// <summary>
/// Divides two big integers.
/// Also modifies <paramref name="digitsPtr1" /> and <paramref name="length1"/> (it will contain remainder).
/// </summary>
/// <param name="digitsPtr1">First big integer digits.</param>
/// <param name="digitsBufferPtr1">Buffer for first big integer digits. May also contain remainder.</param>
/// <param name="length1">First big integer length.</param>
/// <param name="digitsPtr2">Second big integer digits.</param>
/// <param name="digitsBufferPtr2">Buffer for second big integer digits. Only temporarily used.</param>
/// <param name="length2">Second big integer length.</param>
/// <param name="digitsResPtr">Resulting big integer digits.</param>
/// <param name="resultFlags">Which operation results to return.</param>
/// <param name="cmpResult">Big integers comparsion result (pass -2 if omitted).</param>
/// <returns>Resulting big integer length.</returns>
virtual unsafe public uint DivMod(
uint *digitsPtr1,
uint *digitsBufferPtr1,
ref uint length1,
uint *digitsPtr2,
uint *digitsBufferPtr2,
uint length2,
uint *digitsResPtr,
DivModResultFlags resultFlags,
int cmpResult)
{
// Base implementation covers some special cases
bool divNeeded = (resultFlags & DivModResultFlags.Div) != 0;
bool modNeeded = (resultFlags & DivModResultFlags.Mod) != 0;
//
// Special cases
//
// Case when length1 == 0
if (length1 == 0)
{
return(0);
}
// Case when both lengths are 1
if (length1 == 1 && length2 == 1)
{
if (divNeeded)
{
*digitsResPtr = *digitsPtr1 / *digitsPtr2;
if (*digitsResPtr == 0)
{
length2 = 0;
}
}
if (modNeeded)
{
*digitsBufferPtr1 = *digitsPtr1 % *digitsPtr2;
if (*digitsBufferPtr1 == 0)
{
length1 = 0;
}
}
return(length2);
}
// Compare digits first (if was not previously compared)
if (cmpResult == -2)
{
cmpResult = DigitOpHelper.Cmp(digitsPtr1, length1, digitsPtr2, length2);
}
// Case when first value is smaller then the second one - we will have remainder only
if (cmpResult < 0)
{
// Maybe we should copy first digits into remainder (if remainder is needed at all)
if (modNeeded)
{
DigitHelper.DigitsBlockCopy(digitsPtr1, digitsBufferPtr1, length1);
}
// Zero as division result
return(0);
}
// Case when values are equal
if (cmpResult == 0)
{
// Maybe remainder must be marked as empty
if (modNeeded)
{
length1 = 0;
}
// One as division result
if (divNeeded)
{
*digitsResPtr = 1;
}
return(1);
}
// Case when second length equals to 1
if (length2 == 1)
{
// Call method basing on fact if div is needed
uint modRes;
if (divNeeded)
{
length2 = DigitOpHelper.DivMod(digitsPtr1, length1, *digitsPtr2, digitsResPtr, out modRes);
}
else
{
modRes = DigitOpHelper.Mod(digitsPtr1, length1, *digitsPtr2);
}
// Maybe save mod result
if (modNeeded)
{
if (modRes != 0)
{
length1 = 1;
*digitsBufferPtr1 = modRes;
}
else
{
length1 = 0;
}
}
return(length2);
}
// This is regular case, not special
return(uint.MaxValue);
}
