private static BitArray CompressPostingList(int[] posList)
{
var bitsArrays = new BitArray[posList.Length];
for (int i = 0; i < posList.Length; i++)
{
var binary = new List<int>();
while (posList[i] != 0)
{
binary.Add(posList[i]%2);
posList[i] /= 2;
}
binary.Reverse();
if (binary.Count != 0)
{
bitsArrays[i] = new BitArray(binary.Count*2 - 1);
for (int j = 0; j < binary.Count - 1; j++)
{
bitsArrays[i][j] = true;
}
bitsArrays[i][binary.Count - 1] = false;
for (int j = 1; j < binary.Count; j++)
{
bitsArrays[i][j + binary.Count - 1] = binary[j] == 1;
}
}
}
int resultLength = bitsArrays.Select(n => n.Length).Sum();
var result = new BitArray(resultLength);
int k = 0;
for (int i = 0; i < bitsArrays.Length; i++)
{
for (int j = 0; j < bitsArrays[i].Length; j++)
{
result[k++] = bitsArrays[i][j];
}
}
return result;
}
