public int Rank(bool b, int stop, out WaveletTreeNodeBin next, out bool done)
{
if (!groupMembership.ContainsKey(b)) {
next = null;
done = true;
return 0;
}
else {
bool bit = groupMembership[b];
int rank = bitString.Rank(bit, stop);
next = bit ? right : left;
done = next == null;
return rank;
}
}
public WaveletTreeNodeBin(BitArray text, NodeList leaves)
{
List<bool> distinctChars = new List<bool>();
if (text.HasZeros())
distinctChars.Add(false);
if (text.HasOnes())
distinctChars.Add(true);
// Leaf Node
if (distinctChars.Count == 1) {
BitArray bitArray = new BitArray(text.Length);
bitString = new BitString(bitArray);
groupMembership = new Dictionary<bool, bool>();
groupMembership[text[0]] = false;
left = null;
right = null;
leaves.Add(text[0], this);
}
// Inner Node
else {
groupMembership = new Dictionary<bool, bool>(2);
groupMembership[false] = false;
groupMembership[true] = true;
BitArray group1 = new BitArray(0);
BitArray group2 = new BitArray(0);
BitArray bitArray = new BitArray(text.Length);
for (int i = 0; i < text.Length; i++) {
if (text[i] == false) {
group1 = group1.Append(false);
bitArray[i] = false;
}
else {
group2 = group2.Append(true);
bitArray[i] = true;
}
}
bitString = new BitString(bitArray);
left = new WaveletTreeNodeBin(group1, leaves);
right = new WaveletTreeNodeBin(group2, leaves);
left.parent = right.parent = this;
}
}
public WaveletTreeBin(BitArray text)
{
leaves = new NodeList();
this.root = new WaveletTreeNodeBin(text, leaves);
}
public int Select(bool b, int count, out WaveletTreeNodeBin next, out bool done)
{
next = null;
done = true;
if (groupMembership == null || !groupMembership.ContainsKey(b))
return -1;
bool bit = groupMembership[b];
int select = bitString.Select(bit, count);
next = parent;
done = next == null;
return select;
}
