diff --git a/README.md b/README.md
index d78def9e3e032c93d73b152948e015d6e033e0f1..a2a7b26d339cdb8c1c53dd5b10428e183d89e034 100644
--- a/README.md
+++ b/README.md
@@ -48,6 +48,7 @@
 - [Algorithm Archive](https://github.com/algorithm-archivists/algorithm-archive)
 - [Grokking the System Design Interview](https://www.educative.io/collection/5668639101419520/5649050225344512)
 - [算法珠玑](https://soulmachine.gitbooks.io/algorithm-essentials/java/)
+- [AlgoCasts 用心做好每一个算法视频](https://algocasts.io)
 
 ## Sponsor
 1. [Lisanaaa](https://github.com/Lisanaaa): **Feel free to see my profile and send me an email if you have any job opportunities.**
diff --git "a/docs/\345\211\221\346\214\207offer/Java/20_NumericStrings/Solution1.java" "b/docs/\345\211\221\346\214\207offer/Java/20_NumericStrings/Solution1.java"
index 88a9c42622fac1258075dfeabe46d281dd3d5ab0..8c1c5a5bae3be62e20c8e5b981a56ade0bedcf03 100644
--- "a/docs/\345\211\221\346\214\207offer/Java/20_NumericStrings/Solution1.java"
+++ "b/docs/\345\211\221\346\214\207offer/Java/20_NumericStrings/Solution1.java"
@@ -43,7 +43,7 @@ public class Solution1 {
 
     private boolean scanInteger(char[] str) {
         // 去除符号
-        while (index < str.length && (str[index] == '+' || str[index] == '-')) {
+       if (index < str.length && (str[index] == '+' || str[index] == '-')) {
             index++;
         }
 
@@ -58,4 +58,4 @@ public class Solution1 {
         // 判断是否存在整数
         return index > start;
     }
-}
\ No newline at end of file
+}