diff --git a/notes/20. 表示数值的字符串.md b/notes/20. 表示数值的字符串.md
index 60527c11..0990b2e0 100644
--- a/notes/20. 表示数值的字符串.md	
+++ b/notes/20. 表示数值的字符串.md	
@@ -1,6 +1,6 @@
 # 20. 表示数值的字符串
 
-[牛客网](https://www.nowcoder.com/practice/e69148f8528c4039ad89bb2546fd4ff8?tpId=13&tqId=11206&tab=answerKey&from=cyc_github)
+[Leetcode](https://leetcode.cn/problems/biao-shi-shu-zhi-de-zi-fu-chuan-lcof/)
 
 ## 题目描述
 
@@ -41,9 +41,9 @@ false
 ```
 
 ```java
-public boolean isNumeric (String str) {
-    if (str == null || str.length() == 0)
+public boolean validNumber(String s) {
+    if (s == null || s.length() == 0)
         return false;
-    return new String(str).matches("[+-]?\\d*(\\.\\d+)?([eE][+-]?\\d+)?");
+    return s.trim().matches("[+-]?(\\d+(\\.\\d*)?|\\.\\d+)([eE][+-]?\\d+)?");
 }
 ```