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

/**Given a binary search tree (BST), find the lowest common ancestor (LCA) node of two given nodes in the BST.

According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes p and q as the lowest node in T that has both p and q as descendants (where we allow a node to be a descendant of itself).” */
/**
 * 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) {
    let current = root;
    while (current) {
      if (p.val > current.val && q.val > current.val) {
        current = current.right;
      } else if (p.val < current.val && q.val < current.val) {
        current = current.left;
      } else {
        // p < curr < q
        return current;
      }
    }
    
      
  };