public CtciTreeNode <T> FindAncestor(CtciTreeNode <T> head, CtciTreeNode <T> nodeP, CtciTreeNode <T> nodeQ)
{
if (head == null || nodeP == null || nodeQ == null)
{
throw new Exception("Incorrect Data");
}
Q08_Result <T> result = FindRecursively(head, nodeP, nodeQ);
return(result.Node);
}
protected Q08_Result <T> FindRecursively(CtciTreeNode <T> head, CtciTreeNode <T> nodeP, CtciTreeNode <T> nodeQ)
{
if (head == null)
{
return(new Q08_Result <T>(null, false));
}
if (head == nodeP && head == nodeQ)
{
return(new Q08_Result <T>(head, true));
}
Q08_Result <T> resultLeft = FindRecursively(head.Left, nodeP, nodeQ);
if (resultLeft.IsAncestor)
{
return(resultLeft);
}
Q08_Result <T> resultRight = FindRecursively(head.Right, nodeP, nodeQ);
if (resultRight.IsAncestor)
{
return(resultRight);
}
if (resultLeft.Node != null && resultRight.Node != null)
{
return(new Q08_Result <T>(head, true));
}
else if (head == nodeP || head == nodeQ)
{
bool isAncestor = resultLeft.Node != null || resultRight.Node != null;
return(new Q08_Result <T>(head, isAncestor));
}
else
{
return(new Q08_Result <T>(resultLeft.Node != null ? resultLeft.Node : resultRight.Node, false));
}
}