235-lowest-common-ancestor-of-a-binary-search-tree.js

/**
 * 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) {
    while (root !== null) {
        if (root.val < p.val && root.val < q.val) {
            root = root.right;
        } else if (root.val > p.val && root.val > q.val) {
            root = root.left;
        } else {
            return root;
        }
    }
};