/// <summary>
/// Search through the current tree and return the first
/// node without a complete set of children. The arc
/// number for the first missing child is returned in
/// position 0 of the arcNum array.
/// </summary>
/// <param name="node">The node at which to begin the search.</param>
/// <param name="arcNum">An integer array of size 1. The arc
/// number for the first missing child is
/// returned in arcNum[0].</param>
/// <returns>A reference to the first incomplete node
/// in the tree (farthest left). The method
/// returns null if the tree is already complete,
/// or if the tree is empty.</returns>
public DecisionTreeNode findIncompleteNode(DecisionTreeNode node, int[] arcNum)
{
// The search is recursive - at some point, we
// may want to change this to a non-recursive
// algorithm (if we start dealing with extremely
// large trees?)
// Base cases.
if (node == null || node.isLeaf())
{
return(null);
}
// Recursive case. This node is not a leaf - so descend.
for (int i = 0; i < node.getArcLabelCount(); i++)
{
DecisionTreeNode nextNode;
if ((nextNode = findIncompleteNode(node.getChild(i), arcNum)) != null)
{
return(nextNode);
}
}
if ((arcNum[0] = node.getFirstMissingChild()) >= 0)
{
// We found a node with a missing child, which
// is already stored in arcNum - so return this
// node.
return(node);
}
// We searched all the subtrees attached to this
// node, and didn't find anything, so return null.
return(null);
}
/// <summary>
/// Search through the current tree and return the first
/// node without a complete set of children. The arc
/// number for the first missing child is returned in
/// position 0 of the arcNum array.
/// </summary>
/// <param name="node">The node at which to begin the search.</param>
/// <param name="arcNum">An integer array of size 1. The arc
/// number for the first missing child is
/// returned in arcNum[0].</param>
/// <returns>A reference to the first incomplete node
/// in the tree (farthest left). The method
/// returns null if the tree is already complete,
/// or if the tree is empty.</returns>
public DecisionTreeNode findIncompleteNode(DecisionTreeNode node, int[] arcNum)
{
// The search is recursive - at some point, we
// may want to change this to a non-recursive
// algorithm (if we start dealing with extremely
// large trees?)
// Base cases.
if (node == null || node.isLeaf())
{
return null;
}
// Recursive case. This node is not a leaf - so descend.
for (int i = 0; i < node.getArcLabelCount(); i++)
{
DecisionTreeNode nextNode;
if ((nextNode = findIncompleteNode(node.getChild(i), arcNum)) != null)
{
return nextNode;
}
}
if ((arcNum[0] = node.getFirstMissingChild()) >= 0)
{
// We found a node with a missing child, which
// is already stored in arcNum - so return this
// node.
return node;
}
// We searched all the subtrees attached to this
// node, and didn't find anything, so return null.
return null;
}