0700-search-in-a-binary-search-tree.js

/**
 * @param {TreeNode} root
 * @param {number} val
 * @return {TreeNode}
 */
var searchBST = function(root, val) {
    if (root === null) {
        return null;
    }
    if (root.val === val) {
        return root;
    }
    if (root.val < val) {
        return searchBST(root.right, val);
    }
    return searchBST(root.left, val);
};