feat: 字符串问题

Author: luzhipeng

README.en.md

@@ -202,6 +202,7 @@ The data structures mainly includes:
 - [Dynamic Programming](./thinkings/dynamic-programming.md)
 - [Huffman Encode and Run Length Encode](./thinkings/run-length-encode-and-huffman-encode.md)
 - [Bloom Filter](./thinkings/bloom-filter.md)
+- [String Problems](./thinkings/string-problems.md)
 
 
 

README.md

@@ -198,6 +198,7 @@ leetcode 题解，记录自己的 leetcode 解题之路。
 - [动态规划](./thinkings/dynamic-programming.md)
 - [哈夫曼编码和游程编码](./thinkings/run-length-encode-and-huffman-encode.md)
 - [布隆过滤器](./thinkings/bloom-filter.md)
+- [字符串问题](./thinkings/string-problems.md)
 
 ### anki 卡片