BinaryTreeNode* getCommonAncestor(BinaryTreeNode* root, BinaryTreeNode* firstNode, BinaryTreeNode* secondNode)
{
if (root == NULL || firstNode == NULL || secondNode == NULL)
{
return NULL;
}
int firstNodeDepth = getNodeDepth(root, firstNode);
int secondNodeDepth = getNodeDepth(root, firstNode);
int diff = firstNodeDepth - secondNodeDepth;
bool firstPathLonger = true;
if (firstNodeDepth < secondNodeDepth)
{
diff = secondNodeDepth - firstNodeDepth;
firstPathLonger = false;
}
if (firstPathLonger)
{
alignByTrail(firstNode, diff);
}
else
{
alignByTrail(secondNode, diff);
}
while (firstNode != NULL && firstNode != secondNode)
{
firstNode = firstNode->parent;
secondNode = secondNode->parent;
}
return firstNode;
}
//------------------------------------------------------------------------------
// Compute node depth (i.e, height above root). Based on COMPONENT 2.0 code,
// assumes count is set to 0 prior to calling code
void Tree::getNodeDepth(NodePtr p)
{
if (p)
{
p->SetDepth (count);
count++;
getNodeDepth (p->GetChild());
count--;
getNodeDepth (p->GetSibling());
}
}
//------------------------------------------------------------------------------
// Compute node depth (i.e, height above root).
void Tree::GetNodeDepths ()
{
count = 0;
getNodeDepth (Root);
}
