// Helper method for {@link #GetAverageDepthOfLeaves()}.
// Returns the node count for a given node by regarding the node itself and all of
// its successors.
private int CountTotalLeafRecursively(HybridTrieNode node, int leavesCounter)
{
if (node != null)
{
if (!node.HasChildren())
{
leavesCounter++;
}
leavesCounter = CountTotalLeafRecursively(node.LeftChild, leavesCounter);
leavesCounter = CountTotalLeafRecursively(node.RightChild, leavesCounter);
leavesCounter = CountTotalLeafRecursively(node.MiddleChild, leavesCounter);
}
return(leavesCounter);
}
// Helper method for {@link #GetAverageDepthOfLeaves()}.
private int CountTotalLeafDepthRecursively(HybridTrieNode node, int depthCounter, int totalDepth)
{
if (node != null)
{
depthCounter++;
if (!node.HasChildren())
{
totalDepth += depthCounter;
}
totalDepth = CountTotalLeafDepthRecursively(node.LeftChild, depthCounter, totalDepth);
totalDepth = CountTotalLeafDepthRecursively(node.RightChild, depthCounter, totalDepth);
totalDepth = CountTotalLeafDepthRecursively(node.MiddleChild, depthCounter, totalDepth);
}
return(totalDepth);
}
private bool RemoveRecursively(HybridTrieNode parent, HybridTrieNode node, char[] key, int position)
{
if (node == null)
{
return(false);
}
var log = true;
if (key[position] < node.Character)
{
log = RemoveRecursively(node, node.LeftChild, key, position);
}
else if (key[position] > node.Character)
{
log = RemoveRecursively(node, node.RightChild, key, position);
}
else
{
// If we are on our last character.
if (position == key.Length - 1)
{
if (node.IsFinalNode())
{
// The node is an end node, remove the end value.
node.MakeFinalNode(0);
}
else
{
// If there is no end key as it does not exist within the tree.
return(false);
}
}
else if (position < key.Length + 1)
{
log = RemoveRecursively(node, node.MiddleChild, key, position + 1);
}
}
// Only remove if the node's middle child is null and if the node is not an end key.
// If log is false, the value has never been found. Thus the key does not exist within this tree.
if (log && node.MiddleChild == null && !node.IsFinalNode())
{
// Case 1: No children, safe to delete.
if (!node.HasChildren())
{
Transplant(parent, node, null);
}
// Case 2: Right is null, transplant it to left.
else if (node.RightChild == null)
{
Transplant(parent, node, node.LeftChild);
}
// Case 3: Left is null, transplant it to right.
else if (node.LeftChild == null)
{
Transplant(parent, node, node.RightChild);
}
// Case 4: Both left and right children exists, find successor and transplant.
else
{
HybridTrieNode successor = FindSuccessor(node.RightChild);
HybridTrieNode successorParent = FindSuccessorParent(successor);
// If successor node has left child(ren).
if (successorParent != node)
{
Transplant(parent, node, node.RightChild);
}
else
{
Transplant(parent, node, successor);
}
// Make the node's left child as left child for successor node.
successor.LeftChild = node.LeftChild;
}
node = null;
}
return(log);
}
