/// <summary>
/// D.
/// Converts the big number from this instance to long number.
/// Checks that the number can fit into long. If so, returns it.
/// The biggest positive value that can be hold by long variable is: 2^63 -1,
/// therfore has 63 bits.
/// </summary>
/// <returns>longNumber</returns>
public long?BigToLong()
{
BigNum copyNumber = new BigNum(this);
long? longNumber;
int fromBase = 2;
bool isNegative = false;
if (IsNegative)
{
// Make copyNumber represented as positive number.
copyNumber.Complement();
copyNumber.AddNum(GlobalVariables.one);
isNegative = true;
}
if (IsBigNumFitsIntoLongType(copyNumber))
{
longNumber = Convert.ToInt64(copyNumber.WriteNum(), fromBase);
if (isNegative)
{
longNumber = -longNumber;
}
}
else
{
longNumber = null;
Console.WriteLine($"Convertion from BigNum to long is not possible," +
$"this BigNum has more then {GlobalVariables.MaxNumberOfDigitsInLongType} digits");
}
return(longNumber);
}
/// <summary>
/// I.
/// Gets BigNum type and substract between the current value of the binary number with the given one.
/// Let do substraction A = A-B. We know that A-B = A + (-B).
/// Calculating -B: Doing complement and then add 1.
/// </summary>
/// <param name="numberToSubtract"></param>
public void SubNum(BigNum numberToSubtract)
{
// numberToSubstract = B.
BigNum modifiedNumberToSubtract = new BigNum(numberToSubtract);
modifiedNumberToSubtract.Complement(); // numberToSubtract = -B - 1.
modifiedNumberToSubtract.AddNum(GlobalVariables.one); // numberToSubtract = -B.
AddNum(modifiedNumberToSubtract); // Allready updates <mMSB1Location>.
UpdateMSB1Location();
}
public static void D()
{
Console.WriteLine("(D) Using BigToLong method.");
BigNum bigNumC1 = new BigNum(35L);
long? num1 = bigNumC1.BigToLong();
Console.WriteLine(num1);
BigNum bigNumC2 = new BigNum(9223372036854775807L);
long? num2 = bigNumC2.BigToLong();
Console.WriteLine(num2);
BigNum bigNumD = new BigNum();
bigNumD.Complement();
long?num3 = bigNumD.BigToLong();
Console.WriteLine(num3);
Console.WriteLine();
}