What are some practice problems for binary search trees?

What are some practice problems for binary search trees?

Here are a few practice problems for binary search trees:

1. Implement a function to insert a node into a BST.
2. Write a function to find the height of a BST.
3. Create a function to check if a tree is a valid BST.
4. Implement an in-order traversal of a BST.
5. Write a function to find the lowest common ancestor of two nodes in a BST.

Can you explain how to check if a tree is a valid BST?

To check if a tree is a valid BST, you can use a recursive function that ensures:

1. The left subtree contains only nodes with values less than the current node.
2. The right subtree contains only nodes with values greater than the current node.
3. Both subtrees must also be valid BSTs. You can pass the current node's value as a boundary for the left and right subtrees.

What is the time complexity of inserting a node in a BST?

The average time complexity for inserting a node in a BST is O(log n), where n is the number of nodes in the tree. However, in the worst case (when the tree becomes unbalanced), it can degrade to O(n).