diff --git a/problems/0383.赎金信.md b/problems/0383.赎金信.md
index eb83d3ec..1d739173 100644
--- a/problems/0383.赎金信.md
+++ b/problems/0383.赎金信.md
@@ -104,7 +104,7 @@ public:
 };
 ```
 
-* 时间复杂度: O(n)
+* 时间复杂度: O(m+n)，其中m表示ransomNote的长度，n表示magazine的长度
 * 空间复杂度: O(1)
 
 
@@ -470,3 +470,4 @@ bool canConstruct(char* ransomNote, char* magazine) {
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">
   <img src="../pics/网站星球宣传海报.jpg" width="1000"/>
 </a>
+