diff --git a/notes/剑指 offer 题解.md b/notes/剑指 offer 题解.md
index 1b31b7b4..dcd92668 100644
--- a/notes/剑指 offer 题解.md	
+++ b/notes/剑指 offer 题解.md	
@@ -147,7 +147,11 @@ public boolean Find(int target, int [][] array) {
 
 **ÌâÄ¿ÒªÇó**
 
-ÒÔ O(1) µÄ¿Õ¼ä¸´ÔÓ¶ÈÀ´Çó½â¡£
+ÒÔ O(1) µÄ¿Õ¼ä¸´ÔÓ¶ÈºÍ O(n) µÄ¿Õ¼ä¸´ÔÓ¶ÈÀ´Çó½â¡£
+
+**½âÌâ˼·**
+
+´ÓºóÏòÇ°¸Ä±ä×Ö·û´®¡£
 
 ```java
 public String replaceSpace(StringBuffer str) {
@@ -188,6 +192,23 @@ public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
 }
 ```
 
+ʹÓà Stack
+
+```java
+public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
+    Stack<Integer> stack = new Stack<>();
+    while (listNode != null) {
+        stack.add(listNode.val);
+        listNode = listNode.next;
+    }
+    ArrayList<Integer> ret = new ArrayList<>();
+    while (!stack.isEmpty()) {
+        ret.add(stack.pop());
+    }
+    return ret;
+}
+```
+
 µÝ¹é
 
 ```java