static void Main(string[] args)
{
TBinaryTreeOperations objOps = new TBinaryTreeOperations();
//1. Create a Binary Search Tree
TBinaryTree root = null;
root = objOps.NodeInsert(root, 8); //Root node
root = objOps.NodeInsert(root, 10);
root = objOps.NodeInsert(root, 6);
root = objOps.NodeInsert(root, 5);
root = objOps.NodeInsert(root, 4);
root = objOps.NodeInsert(root, 7);
root = objOps.NodeInsert(root, 12);
root = objOps.NodeInsert(root, 14);
root = objOps.NodeInsert(root, 9);
//2. Count the nodes
//int cnt = objOps.CountBSTNodes(root);
//3. Search in BST
//bool isFound = objOps.LookupBST(root, 0);
//4. Remove/Delete a node
//TBinaryTree newroot = objOps.DeleteFromBST(root, 5);
//5. isBST : Return true if a binary tree is a Binary Search Tree
bool IsBST;
//6. FindDepth
//7. MaxDepth
//8. MinValue
//TBinaryTree Min = objOps.FindMin(root);
//9. PrintTree
//10. Print PostOrder
//11. hasPathSum
//12. PrintPath
//13. Mirror
//14. DoubleTree
//15. SameTree
//16. CountTrees
//17.
}
//2. Count the number of Nodes
public int CountBSTNodes(TBinaryTree root)
{
if (root == null)
{
return(0);
}
else
{
return(CountBSTNodes(root.left) + CountBSTNodes(root.right) + 1);
}
}
public TBinaryTree FindMin(TBinaryTree root)
{
if (root == null)
{
return(root);
}
while (root.left != null)
{
root = root.left;
}
return(root);
}
private int FindMaxVal(TBinaryTree root)
{
if (root == null)
{
return(0);
}
while (root.right != null)
{
root = root.right;
}
return(root.data);
}
private int FindMinVal(TBinaryTree root)
{
if (root == null)
{
return(0);
}
while (root.left != null)
{
root = root.left;
}
return(root.data);
}
//4. Remove a node
public TBinaryTree DeleteFromBST(TBinaryTree root, int target)
{
if (root == null)
{
return(null);
}
else if (target < root.data)
{
root.left = DeleteFromBST(root.left, target);
}
else if (target > root.data)
{
root.right = DeleteFromBST(root.right, target);
}
else //Found the node
{
//Case 1. No left and right
if (root.left == null && root.right == null)
{
root = null;
}
//case 2. Either left is null (one child)
else if (root.left == null)
{
TBinaryTree temp = root;
temp.data = root.right.data;
temp = root.right;
temp = null;
}
else if (root.right == null)
{
TBinaryTree temp = root;
temp.data = root.left.data;
temp = root.left;
temp = null;
}
//Case 3 : Both L & R not null
else
{
TBinaryTree temp = FindMin(root);
root.data = temp.data;
root.right = DeleteFromBST(root.right, temp.data);
}
}
return(root);
}
//1. Insert a node in BST
public TBinaryTree NodeInsert(TBinaryTree root, int data)
{
if (root == null)
{
root = new TBinaryTree(data);
}
else if (data <= root.data)
{
root.left = NodeInsert(root.left, data);
}
else if (data > root.data)
{
root.right = NodeInsert(root.right, data);
}
return(root);
}
//3. Lookup
public bool LookupBST(TBinaryTree root, int target)
{
if (root == null)
{
return(false);
}
else if (target == root.data)
{
return(true);
}
else if (target < root.data)
{
return(LookupBST(root.left, target));
}
else
{
return(LookupBST(root.right, target));
}
}
public bool IsBST(TBinaryTree root)
{
if (root == null)
{
return(true);
}
if (root.left != null && FindMinVal(root.left) > root.data)
{
return(false);
}
if (root.right != null && FindMaxVal(root.right) < root.data)
{
return(false);
}
return(true);
}