-lowest-common-ancestor-of-a-binary-tree.py

class Solution:
    def lowestCommonAncestor(self, root: 'TreeNode', p: 'TreeNode', q: 'TreeNode') -> 'TreeNode':
        # In base case, the `not root` is the null case, other cases means we have found the node we are looking for
        if not root or root == p or root == q: 
            return root
        
        x = self.lowestCommonAncestor(root.left, p, q)
        y = self.lowestCommonAncestor(root.right, p, q)
        
        if (x and y) or root in [p,q]: # root in [p,q] as node can be ancestor of itself
            return root
        else:
            return x or y # if either of one is found then return that node