From 91c6ecdee95f5eb97b53590a81e242ef6d5f75c7 Mon Sep 17 00:00:00 2001
From: wz-mibookwindows <wzlylv@163.com>
Date: Sat, 7 Aug 2021 11:04:11 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BC=98=E5=8C=96=20707=E8=AE=BE=E8=AE=A1?=
 =?UTF-8?q?=E9=93=BE=E8=A1=A8=20addAtIndex?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 problems/0707.设计链表.md | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/problems/0707.设计链表.md b/problems/0707.设计链表.md
index f7b03c8b..5e748a24 100644
--- a/problems/0707.设计链表.md
+++ b/problems/0707.设计链表.md
@@ -917,16 +917,17 @@ class MyLinkedList {
     }
 
     fun addAtIndex(index: Int, `val`: Int) {
-        if (index == 0) return addAtHead(`val`)
-        if (index == size) return addAtTail(`val`)
         if (index > size) return
-        var cur = this.next
-        for (i in 0 until index - 1) {
+        val pre = ListNode(0)
+        pre.next = this.next
+        var cur:ListNode? = pre
+        for (i in 0 until index) {
             cur = cur?.next
         }
         val temp = cur?.next
         cur?.next = ListNode(`val`)
         cur?.next?.next = temp
+        this.next = pre.next
         size++
     }