/// <summary>
/// Decodes a polynomial encoded with ToBinary()
/// </summary>
///
/// <param name="InputStream">An input stream containing an encoded polynomial</param>
/// <param name="N">Number of coefficients in the polynomial</param>
///
/// <returns>The decoded polynomial</returns>
public static SparseTernaryPolynomial FromBinary(MemoryStream InputStream, int N)
{
BinaryReader br = new BinaryReader(InputStream);
// number of coefficients equal to 1
int numOnes = IntUtils.ReadShort(InputStream);
// number of coefficients equal to -1
int numNegOnes = IntUtils.ReadShort(InputStream);
int maxIndex = 1 << BITS_PER_INDEX;
int bitsPerIndex = 32 - IntUtils.NumberOfLeadingZeros(maxIndex - 1);
int data1Len = (numOnes * bitsPerIndex + 7) / 8;
byte[] data1 = ArrayEncoder.ReadFullLength(InputStream, data1Len);
int[] ones = ArrayEncoder.DecodeModQ(data1, numOnes, maxIndex);
int data2Len = (numNegOnes * bitsPerIndex + 7) / 8;
byte[] data2 = ArrayEncoder.ReadFullLength(InputStream, data2Len);
int[] negOnes = ArrayEncoder.DecodeModQ(data2, numNegOnes, maxIndex);
return(new SparseTernaryPolynomial(N, ones, negOnes));
}