private static BstNode GetNewNode(int data)
{
BstNode newNode = new BstNode();
newNode.Data = data;
return(newNode);
}
public static void TraverseTreeDFS(BstNode tree)
{
if (tree != null)
{
var data = tree.Data;
TraverseTreeDFS(tree.Left);
Console.Write(tree.Data + " ");
TraverseTreeDFS(tree.Right);
}
}
private static bool IsBstUtil(BstNode root, int minvalue, int maxvalue)
{
if (root == null)
{
return(true);
}
if (root.Data > minvalue && root.Data < maxvalue &&
IsBstUtil(root.Left, minvalue, root.Data) && IsBstUtil(root.Right, root.Data, maxvalue))
{
return(true);
}
else
{
return(false);
}
}
public static int GetHeight(BstNode root)
{
int leftHeight = 0;
int rightHeight = 0;
if (root == null)
{
return(-1);
}
leftHeight = GetHeight(root.Left);
rightHeight = GetHeight(root.Right);
int height = Math.Max(leftHeight, rightHeight) + 1;
return(height);
}
public static BstNode FindMax(BstNode root)
{
if (root == null)
{
//Console.WriteLine("Item not found");
return(root);
}
else if (root.Right == null)
{
return(root);
}
else
{
return(FindMax(root.Right));
}
}
public static void TraverseBFS(BstNode tree)
{
Console.Write("BFS: ");
Queue <BstNode> discoveredNodes = new Queue <BstNode>();
discoveredNodes.Enqueue(tree);
while (discoveredNodes.Count > 0)
{
var node = discoveredNodes.Dequeue();
Console.Write(node.Data + " ");
if (node.Left != null)
{
discoveredNodes.Enqueue(node.Left);
}
if (node.Right != null)
{
discoveredNodes.Enqueue(node.Right);
}
}
Console.WriteLine();
}
public void Insert(int data)
{
if (root == null)
{
BstNode newNode = GetNewNode(data);
root = newNode;
}
else
{
if (data < root.Data)
{
var left = Insert(root.Left, data);
root.Left = left;
}
else
{
var right = Insert(root.Right, data);
root.Right = right;
}
}
}
private BstNode Insert(BstNode root, int data)
{
if (root == null)
{
BstNode newNode = GetNewNode(data);
root = newNode;
}
else
{
if (data < root.Data)
{
var left = Insert(root.Left, data);
root.Left = left;
}
else
{
var right = Insert(root.Right, data);
root.Right = right;
}
}
return(root);
}
public static int FindItem(BstNode root, int data)
{
if (root == null)
{
//Console.WriteLine("Item not found");
return(-1);
}
else if (root.Data == data)
{
return(root.Data);
}
else
{
if (root.Data > data)
{
return(FindItem(root.Left, data));
}
else
{
return(FindItem(root.Right, data));
}
}
}
//private bool IsSubtreeGreater(BstNode right, int data)
//{
// if (right.Data >= data && IsSubtreeGreater(right.Right, data) && IsSubtreeLesser(right.Left, data))
// {
// return true;
// }
// else
// return false;
//}
//private bool IsSubtreeLesser(BstNode left, int data)
//{
// if (left.Data <= data && IsSubtreeGreater(left.Right, data) && IsSubtreeLesser(left.Left, data))
// {
// return true;
// }
// else
// return false;
//}
public static BstNode Delete(BstNode root, int data)
{
if (root == null)
{
return(root);
}
if (data < root.Data)
{
root.Left = Delete(root.Left, data);
}
else if (data > root.Data)
{
root.Right = Delete(root.Right, data);
}
else
{
if (root.Left == null && root.Right == null)
{
root = null;
}
else if (root.Left == null)
{
root = root.Right;
}
else if (root.Right == null)
{
root = root.Left;
}
else
{
var node = FindMin(root.Right);
root.Data = node.Data;
root.Right = Delete(root.Right, node.Data);
}
}
return(root);
}
public static bool IsBinarySearchTree(BstNode root)
{
return(IsBstUtil(root, int.MinValue, int.MaxValue));
}