index.js

const { make_tree } = require('../utils');
/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @param {TreeNode} p
 * @param {TreeNode} q
 * @return {TreeNode}
 */
var lowestCommonAncestor = function(root, p, q) {
    if (root.val > p.val && root.val > q.val) {
        return lowestCommonAncestor(root.left, p, q);
    }
    if (root.val < p.val && root.val < q.val) {
        return lowestCommonAncestor(root.right, p, q);
    }
    return root;
};

const nodes = make_tree([6,2,8,0,4,7,9,null,null,3,5], [0, 1, 4]);
console.log(lowestCommonAncestor(nodes[0], nodes[2], nodes[1]));

// console.log(nodes);