private static ulong End(sbyte[] trits, int index)
{
if (TritsHelper.Trits2Long(trits, index, Constants.TritsPerTryte) > 0)
{
return(Constants.TritsPerTryte);
}
return(Constants.TritsPerTryte + End(trits, index + Constants.TritsPerTryte));
}
public static Tuple <long, int> Decode(sbyte[] trits)
{
// check Zero
ulong index;
for (index = 0; index < 4; index++)
{
if (trits[index] != Zero[index])
{
break;
}
}
if (index == 4)
{
return(new Tuple <long, int>(0, 4));
}
//
var encodersStart = End(trits, 0);
var inputEnd = encodersStart +
PascalMinTrits((ulong)Math.Pow(2, (long)(encodersStart / Constants.TritsPerTryte)) - 1);
var encoder = TritsHelper.Trits2Long(trits, (int)encodersStart, (int)(inputEnd - encodersStart));
long acc = 0;
int i = 0;
index = 0;
for (; index < encodersStart; index += Constants.TritsPerTryte, i++)
{
ulong left = encodersStart - index;
int length = left > Constants.TritsPerTryte ? Constants.TritsPerTryte : (int)left;
long temp = TritsHelper.Trits2Long(trits, (int)index, length);
if (((encoder >> i) & 0x1L) != 0x0L)
{
temp = -temp;
}
acc += (long)(Math.Pow(27, i)) * temp;
}
return(new Tuple <long, int>(acc, (int)inputEnd));
}
public static void Encode(long input, sbyte[] trits)
{
if (input == 0)
{
Array.Copy(Zero, trits, Zero.Length);
}
else
{
int length = (int)TritsHelper.RoundThird((long)PascalMinTrits((ulong)Math.Abs(input)));
long encoding = 0;
TritsHelper.Long2Trits(input, trits);
int index = 0;
int end = length - Constants.TritsPerTryte;
for (int i = 0; i < end; i += Constants.TritsPerTryte)
{
int n = end - i > Constants.TritsPerTryte ? Constants.TritsPerTryte : end - i;
if (TritsHelper.Trits2Long(trits, i, n) > 0)
{
encoding |= (1L << index);
for (int j = 0; j < n; j++)
{
trits[i + j] = (sbyte)-trits[i + j];
}
}
index += 1;
}
if (TritsHelper.Trits2Long(trits, length - Constants.TritsPerTryte, Constants.TritsPerTryte) < 0)
{
encoding |= (1L << index);
for (int j = 0; j < Constants.TritsPerTryte; j++)
{
trits[length - Constants.TritsPerTryte + j] =
(sbyte)-trits[length - Constants.TritsPerTryte + j];
}
}
sbyte[] encodingTrits = new sbyte[trits.Length - length];
TritsHelper.Long2Trits(encoding, encodingTrits);
Array.Copy(encodingTrits, 0, trits, length, encodingTrits.Length);
}
}
