Add 4th edition book to alpha order

Author: colmwoods

books/free-programming-books-subjects.md

@@ -102,13 +102,13 @@ Books that cover a specific programming language can be found in the [BY PROGRAM
 * [Algorithmic Thinking](https://labuladong.gitbook.io/algo-en) - Donglai Fu
 * [Algorithms](https://en.wikibooks.org/wiki/Algorithms) - Wikibooks
 * [Algorithms](https://jeffe.cs.illinois.edu/teaching/algorithms/book/Algorithms-JeffE.pdf) - Jeff Erickson (PDF)
+* [Algorithms, 4th Edition](https://algs4.cs.princeton.edu/home/) - Robert Sedgewick, Kevin Wayne
 * [Algorithms and Automatic Computing Machines (1963)](https://archive.org/details/Algorithms_And_Automatic_Computing_Machines) - B. A. Trakhtenbrot
 * [Algorithms and Complexity](https://www.math.upenn.edu/~wilf/AlgoComp.pdf) - Herbert S. Wilf (PDF)
 * [Algorithms and Data Structures](https://textbookequity.org/Textbooks/Nievergelt_Algorithms%20and%20Data%20Structures08.pdf) - Jürg Nievergelt, Klaus Hinrichs (PDF)
 * [Algorithms Course Materials](https://jeffe.cs.illinois.edu/teaching/algorithms/) - Jeff Erickson
 * [Algorithms for Decision Making](https://algorithmsbook.com) - Mykel J. Kochenderfer, Tim A. Wheeler, Kyle H. Wray (HTML, PDF) (CC BY-NC-ND)
 * [Algorithms Notes for Professionals](https://goalkicker.com/AlgorithmsBook) - Compiled from StackOverflow Documentation (PDF)
-* [Algorithms, 4th Edition](https://algs4.cs.princeton.edu/home/) - Robert Sedgewick, Kevin Wayne
 * [An Open Guide to Data Structures and Algorithms](https://open.umn.edu/opentextbooks/textbooks/an-open-guide-to-data-structures-and-algorithms) - Paul W. Bible, Lucas Moser (PDF)
 * [Annotated Algorithms in Python: Applications in Physics, Biology, and Finance](https://github.com/mdipierro/nlib) - Massimo Di Pierro
 * [Binary Trees](http://cslibrary.stanford.edu/110/BinaryTrees.pdf) - Nick Parlante (PDF)