static void Main(string[] args)
{
TreeNode n = new TreeNode(1);
n.left = new TreeNode(0);
n.right = new TreeNode(8);
Program p = new Program();
Console.WriteLine(p.LowestCommonAncestor(n, n.left, n.right).val);
}
public TreeNode LowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q)
{
if (root == null)
return null;
if (!pFound && root == p)
{
if (qFound)
return ancestor;
else
{
pFound = true;
ancestor = p;
}
}
if (!qFound && root == q)
{
if (pFound)
return ancestor;
else
{
qFound = true;
ancestor = q;
}
}
stack.Push(root);
TreeNode r;
r = LowestCommonAncestor(root.left, p, q);
if (r != null)
return r;
r = LowestCommonAncestor(root.right, p, q);
if (r != null)
return r;
stack.Pop();
if (root == ancestor)
ancestor = stack.Peek();
return null;
}
