Consolidated README

README.md

@@ -3,18 +3,15 @@ Elementary Functional Algorithms
 
 Edition: $\displaystyle e = \sum \limits _{n=0}^{\infty }{\frac {1}{n!}} = 1 + {\frac {1}{1}}+{\frac {1}{1\cdot 2}}+{\frac {1}{1\cdot 2\cdot 3}}+\cdots = 2.718283$
 
-2023/10
+2023/11
 
-This book introduces about elementary functional algorithms and data structures. It includes side-by-side comparison about purely functional realization and their imperative counterpart, with 120 exercises and answers.
+This book presents elementary functional algorithms and data structures with 120 exercises and answers. I wrote the first edition from 2009 to 2017, then rewrote from 2020 to 2023. The **second edition** in PDF can be **downloaded** ([EN](https://github.com/liuxinyu95/AlgoXY/files/13211742/algoxy-en.pdf), [中文](https://github.com/liuxinyu95/AlgoXY/files/13211747/algoxy-zh-cn.pdf)). The first edition in Chinese ([中文](https://book.douban.com/subject/26931430/)) was published in 2017.
 
 <img src="https://user-images.githubusercontent.com/332938/95418499-442e4b00-096a-11eb-81b9-496020aa5f10.jpg" width="400">
 
 Contents
 --------
 
-I am adding exercises and answers to the **second edition** from 2023/03 (added 120 answers as of 2023/10). I wrote the first edition from 2009 to 2017, then rewrote from 2020 to 2023. The PDF can be **downloaded** ([EN](https://github.com/liuxinyu95/AlgoXY/files/13211742/algoxy-en.pdf), [中文](https://github.com/liuxinyu95/AlgoXY/files/13211747/algoxy-zh-cn.pdf)). The 1st edition in Chinese ([中文](https://book.douban.com/subject/26931430/)) was published in 2017. I switched my focus to the mathematics of programming from 2018, see ([github](https://github.com/liuxinyu95/unplugged)).
-
-
 - Preface
 - Chapter 1, List;
 - Chapter 2, Binary Search Tree;
@@ -58,7 +55,7 @@ You need the GNU make tool, in Debian/Ubuntu like Linux, it can be installed thr
 $ sudo apt-get install build-essential
 ```
 
-In Windows, you can use WSL or install MSYS. In Mac OS X, please install the developer tool from this command line:
+In Windows, you can use WSL or MSYS. In Mac OS X, please install the developer tool from this command line:
 
 ```bash
 $ xcode-select --install