236. Lowest Common Ancestor of a Binary Tree

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

Python

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

        left = self.lowestCommonAncestor(root.left, p, q)
        right = self.lowestCommonAncestor(root.right, p, q)

        if not left or not right:
            # One or more target are not yet reach
            return left if left else right

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

Javascript

var lowestCommonAncestor = function(root, p, q) {
    let res;
  
    const recursive = (node) => {
      if (node === null) return false;
      
      const isLeftMatched = recursive(node.left);
      const isRightMatched = recursive(node.right);
      
      const isMidMatched = node.val === p.val || node.val === q.val;
      
      if ((isLeftMatched && isRightMatched) || (isLeftMatched && isMidMatched) || (isRightMatched && isMidMatched)) res = node;
      
      return isLeftMatched || isRightMatched || isMidMatched;            
    }
    
    recursive(root);
    return res;
};