diff --git a/README.md b/README.md
index f0b89ba1b..549aa5c25 100644
--- a/README.md
+++ b/README.md
@@ -29,6 +29,15 @@
支持 Progressive Web Apps 的题解电子书《LeetCode Cookbook》 Online Reading
+
+
+离线版本的电子书《LeetCode Cookbook》 Download here
+
+
+
+
+
+
## Data Structures
> 标识了 ✅ 的专题是完成所有题目了的，没有标识的是还没有做完所有题目的
diff --git a/leetcode/0717.1-bit-and-2-bit-Characters/README.md b/leetcode/0717.1-bit-and-2-bit-Characters/README.md
index 2573acaca..877c36582 100755
--- a/leetcode/0717.1-bit-and-2-bit-Characters/README.md
+++ b/leetcode/0717.1-bit-and-2-bit-Characters/README.md
@@ -1,7 +1,7 @@
# [717. 1-bit and 2-bit Characters](https://leetcode.com/problems/1-bit-and-2-bit-characters/)
-# 题目:
+## 题目:
We have two special characters. The first character can be represented by one bit `0`. The second character can be represented by two bits (`10` or `11`).
diff --git a/leetcode/0933.Number-of-Recent-Calls/README.md b/leetcode/0933.Number-of-Recent-Calls/README.md
index f4eebfaff..02b2340ce 100644
--- a/leetcode/0933.Number-of-Recent-Calls/README.md
+++ b/leetcode/0933.Number-of-Recent-Calls/README.md
@@ -2,7 +2,7 @@
-### 题目
+## 题目
Write a class `RecentCounter` to count recent requests.
diff --git a/website/content/ChapterFour/0717.1-bit-and-2-bit-Characters.md b/website/content/ChapterFour/0717.1-bit-and-2-bit-Characters.md
index 923e5679d..499889244 100755
--- a/website/content/ChapterFour/0717.1-bit-and-2-bit-Characters.md
+++ b/website/content/ChapterFour/0717.1-bit-and-2-bit-Characters.md
@@ -1,7 +1,7 @@
# [717. 1-bit and 2-bit Characters](https://leetcode.com/problems/1-bit-and-2-bit-characters/)
-# 题目:
+## 题目:
We have two special characters. The first character can be represented by one bit `0`. The second character can be represented by two bits (`10` or `11`).
diff --git a/website/content/ChapterFour/0933.Number-of-Recent-Calls.md b/website/content/ChapterFour/0933.Number-of-Recent-Calls.md
index f4eebfaff..02b2340ce 100644
--- a/website/content/ChapterFour/0933.Number-of-Recent-Calls.md
+++ b/website/content/ChapterFour/0933.Number-of-Recent-Calls.md
@@ -2,7 +2,7 @@
-### 题目
+## 题目
Write a class `RecentCounter` to count recent requests.
diff --git a/website/content/ChapterFour/pytool/GenerateOne.py b/website/content/ChapterFour/pytool/GenerateOne.py
new file mode 100644
index 000000000..233171b52
--- /dev/null
+++ b/website/content/ChapterFour/pytool/GenerateOne.py
@@ -0,0 +1,24 @@
+import os
+from os.path import join
+from shutil import move
+import glob
+
+content = []
+oneFile = 'ChapterTwo_OnePDF.md'
+current_working_dir = os.getcwd()
+# print(f"current_working_dir: {current_working_dir}")
+
+dir_names = glob.glob("*.md")
+dir_names.sort()
+# print(dir_names)
+print(len(dir_names))
+for file_name in dir_names:
+ # print(file_name)
+ with open(file_name, "r") as myfile:
+ content = myfile.read()
+ with open(oneFile, "a") as myfile:
+ myfile.write("\n")
+ myfile.write(content)
+ myfile.write("\n")
+
+print("Finished")
\ No newline at end of file
diff --git a/website/content/ChapterOne/_index.md b/website/content/ChapterOne/_index.md
index e0c1e697d..0aaf6fceb 100644
--- a/website/content/ChapterOne/_index.md
+++ b/website/content/ChapterOne/_index.md
@@ -71,7 +71,7 @@ LeetCode 统计代码运行时长会有波动的，相同的代码提交 10 次
- 本电子书的左上角有搜索栏，可以迅速帮你找到你想看的章节和题号。
- 本电子书每页都接入了 Gitalk，每一页的最下方都有评论框可以评论，如果没有显示出来，请检查自己的网络。
--
+- 关于题解，笔者建议这样使用：先自己读题，思考如何解题。如果 15 分钟还没有思路，那么先看笔者的解题思路，但是不要看代码。有思路以后自己用代码实现一遍。如果完全不会写，那就看笔者提供的代码，找出自己到底哪里不会写，找出问题记下来，这就是自己要弥补的知识漏洞。如果自己实现出来了，提交以后有错误，自己先 debug。AC 以后没有到 100% 也先自己思考如何优化。如果每道题自己都能优化到 100% 了，那么一段时间以后进步会很大。所以总的来说，实在没思路，看解题思路；实在优化不到 100%，看看代码。
## 互动与勘误
diff --git a/website/content/ChapterTwo/Array.md b/website/content/ChapterTwo/Array.md
index da5c58b59..59dfa8f18 100644
--- a/website/content/ChapterTwo/Array.md
+++ b/website/content/ChapterTwo/Array.md
@@ -3,7 +3,7 @@ title: Array
type: docs
---
-## Array
+# Array
| Title | Solution | Difficulty | Time | Space |收藏|
| ----- | :--------: | :----------: | :----: | :-----: | :-----: |
diff --git a/website/content/_index.md b/website/content/_index.md
index 9daa10df6..d2b76d4ef 100644
--- a/website/content/_index.md
+++ b/website/content/_index.md
@@ -70,6 +70,7 @@ LeetCode 统计代码运行时长会有波动的，相同的代码提交 10 次
- 本电子书的左上角有搜索栏，可以迅速帮你找到你想看的章节和题号。
- 本电子书每页都接入了 Gitalk，每一页的最下方都有评论框可以评论，如果没有显示出来，请检查自己的网络。
+- 关于题解，笔者建议这样使用：先自己读题，思考如何解题。如果 15 分钟还没有思路，那么先看笔者的解题思路，但是不要看代码。有思路以后自己用代码实现一遍。如果完全不会写，那就看笔者提供的代码，找出自己到底哪里不会写，找出问题记下来，这就是自己要弥补的知识漏洞。如果自己实现出来了，提交以后有错误，自己先 debug。AC 以后没有到 100% 也先自己思考如何优化。如果每道题自己都能优化到 100% 了，那么一段时间以后进步会很大。所以总的来说，实在没思路，看解题思路；实在优化不到 100%，看看代码。
## 互动与勘误