235. Lowest Common Ancestor of a Binary Search Tree

https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/

Python

First Solution

class Solution:
    def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
        if not root:
            # Leaf, but target not found
            return None

        if root.val == p.val or root.val == q.val:
            # Hit the target, current root is p or q
            return root

        if p.val > root.val and q.val > root.val:
            # Find targets from the right tree
            return self.lowestCommonAncestor(root.right, p, q)
        elif p.val < root.val and q.val < root.val:
            # Find targets from the left tree
            return self.lowestCommonAncestor(root.left, p, q)

        # Both left and right are reaching the targets, current node is the answer
        return root

Second Solution

class Solution:
    def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
        targets = (p.val, q.val)
        
        def find(node):
            if not node:
                return
            
            if node.val in targets:
                return node
            
            if all(node.val > t for t in targets):
                return find(node.left)

            if all(node.val < t for t in targets):
                return find(node.right)
            
            return node
            
            
        return find(root)