diff --git a/problems/0707.设计链表.md b/problems/0707.设计链表.md
index 64472506..ba0e7e3b 100644
--- a/problems/0707.设计链表.md
+++ b/problems/0707.设计链表.md
@@ -282,12 +282,12 @@ Java：
 ```Java
 //单链表
 class ListNode {
-int val;
-ListNode next;
-ListNode(){}
-ListNode(int val) {
-this.val=val;
-}
+    int val;
+    ListNode next;
+    ListNode(){}
+    ListNode(int val) {
+        this.val=val;
+    }
 }
 class MyLinkedList {
     //size存储链表元素的个数