Lowest Common Ancestor of a Binary Tree

import { TreeNode } from '@algorithm/lib';
 
export function lowestCommonAncestor(
  root: TreeNode | null,
  p: TreeNode | null,
  q: TreeNode | null,
): TreeNode | null {
  if (root === null || root.val === p?.val || root.val === q?.val) {
    return root;
  }
  const left = lowestCommonAncestor(root.left, p, q);
  const right = lowestCommonAncestor(root.right, p, q);
  if (left !== null && right !== null) {
    return root;
  }
  return left ?? right;
}