public static UInt32 TargetToBits(UInt256 target)
{
// to get the powerPart: take the log in base 2, round up to 8 to respect byte boundaries, and then remove 24 to represent 3 bytes of precision
var log = Math.Ceiling(UInt256.Log(target, 2) / 8) * 8 - 24;
var powerPart = (byte)(log / 8 + 3);
// determine the multiplier based on the powerPart
var multiplier = BigInteger.Pow(2, 8 * (powerPart - 3));
// to get multiplicand: divide the target by the multiplier
//TODO
var multiplicandBytes = ((BigInteger)target / (BigInteger)multiplier).ToByteArray();
Debug.Assert(multiplicandBytes.Length == 3 || multiplicandBytes.Length == 4);
// this happens when multipicand would be greater than 0x7fffff
// TODO need a better explanation comment
if (multiplicandBytes.Last() == 0)
{
multiplicandBytes = multiplicandBytes.Skip(1).ToArray();
powerPart++;
}
// construct the bits representing the powerPart and multiplicand
var bits = Bits.ToUInt32(multiplicandBytes.Concat(powerPart).ToArray());
return(bits);
}