diff --git a/problems/0235.二叉搜索树的最近公共祖先.md b/problems/0235.二叉搜索树的最近公共祖先.md
index 07e55ba5..a8c94ec9 100644
--- a/problems/0235.二叉搜索树的最近公共祖先.md
+++ b/problems/0235.二叉搜索树的最近公共祖先.md
@@ -328,13 +328,11 @@ var lowestCommonAncestor = function(root, p, q) {
     }
     if(root.val>p.val&&root.val>q.val) {
         // 向左子树查询
-        let left = lowestCommonAncestor(root.left,p,q);
-        return left !== null&&left;
+         return root.left = lowestCommonAncestor(root.left,p,q);
     }
     if(root.val<p.val&&root.val<q.val) {
         // 向右子树查询
-        let right = lowestCommonAncestor(root.right,p,q);
-        return right !== null&&right;
+        return root.right = lowestCommonAncestor(root.right,p,q);
     }
     return root;
 };