How do I delete a node from a binary search tree in Python?

How do I delete a node from a binary search tree in Python?

To delete a node from a binary search tree (BST) in Python, you need to consider three cases: if the node is a leaf, has one child, or has two children. Would you like a code example?

Yes, please provide a code example.

Here's a simple implementation:

class Node:
    def __init__(self, key):
        self.left = None
        self.right = None
        self.val = key


def delete_node(root, key):
    if root is None:
        return root
    if key < root.val:
        root.left = delete_node(root.left, key)
    elif key > root.val:
        root.right = delete_node(root.right, key)
    else:
        if root.left is None:
            return root.right
        elif root.right is None:
            return root.left
        temp = min_value_node(root.right)
        root.val = temp.val
        root.right = delete_node(root.right, temp.val)
    return root


def min_value_node(node):
    current = node
    while current.left is not None:
        current = current.left
    return current

Can you explain how the min_value_node function works?

Sure! The min_value_node function finds the node with the smallest value in a given subtree. It keeps traversing the left child until it reaches the leftmost node, which has the minimum value.