public Node(int data, Node left, Node right, Node parent)
{
this.data = data;
this.left = left;
this.right = right;
this.parent = parent;
}
public Node buildtree(int[] arr)
{
foreach (int i in arr)
root = insert(root, i, null);
return root;
}
static Node FindKthClosestSucc(Node node, int k, List<int> closest)
{
if (node == null)
return null;
if(k == 0)
return node;
if (node.right != null)
{
Node min = minNode(node.right);
if (min != null)
closest.Add(min.data);
return FindKthClosestSucc(min, k - 1, closest);
}
else
{
Node parent = node.parent;
while (parent != null && parent.right == node)
{
node = parent;
parent = node.parent;
}
if (parent != null)
closest.Add(parent.data);
return FindKthClosestSucc(parent, k - 1, closest);
}
}
static Node FindKthClosestPred(Node node, int k, List<int> closest)
{
if (node == null)
return null;
if (k == 0)
return node;
if (node.left != null)
{
Node max = maxNode(node.left);
if (max != null)
closest.Add(max.data);
return FindKthClosestPred(max, k - 1, closest);
}
else
{
Node parent = node.parent;
while (parent != null && parent.left == node)
{
node = parent;
parent = node.parent;
}
if (parent != null)
closest.Add(parent.data);
return FindKthClosestPred(parent, k - 1, closest);
}
}
public static void KthClosest(Node node, int data, int k)
{
Node cur = findNode(node, data);
List<int> closest = new List<int>();
Node KthSucc = FindKthClosestSucc(cur, k, closest);
Node KthPred = FindKthClosestPred(cur, k, closest);
Console.WriteLine("K succs and preds: ");
foreach (int i in closest)
Console.Write("{0} ", i);
}
public Node insert(Node node, int data, Node parent)
{
if (node == null)
return new Node(data, parent);
else {
if (node.data < data)
node.right = insert(node.right, data, node);
else
node.left = insert(node.left, data, node);
return node;
}
}
public Node(int data, Node parent)
: this(data, null, null, parent)
{
}
static Node findNode(Node node, int data)
{
if (node == null)
return null;
if (node.data == data)
return node;
if (node.data < data)
return findNode(node.right, data);
else
return findNode(node.left, data);
}
static Node minNode(Node node)
{
while (node.left != null)
node = node.left;
return node;
}
static Node maxNode(Node node)
{
while (node.right != null)
node = node.right;
return node;
}
