This 2nd edition is essentially modified, more than 1/3 of contents is replaced by a new metarial!
From the reviews of the second edition:
“This is an entertaining and impressive book. I say impressive because the author managed to cover a very large part of combinatorics in 27 short chapters, without assuming any graduate-level knowledge of the material. … The collection of topics covered is another big advantage of the book. … The book is ideal as reference material or for a reading course for a dedicated graduate student. One could teach a very enjoyable class from it as well … .” (Miklós Bóna, The Mathematical Association of America, May, 2012). Full review is here.
"Readers interested in any branch of combinatorics will find this book compelling. ... This book is very suitable for advanced undergraduate and graduate mathematics and computer science majors. It requires a very solid grounding in intermediate-level combinatorics and an appreciation for several proof methods, but it is well worth the study." (G.M. White, ACM Computing Reviews, May 2012)
“This is the second edition of a well-received textbook. It has been extended with new and updated results. Typographical errors in the first edition are corrected. … This textbook is suitable for advanced undergraduate or graduate students as well as researchers working in discrete mathematics or theoretical computer science. The author’s enthusiasm for the subject is evident and his writing is clear and smooth. This is a book deserving recommendation.” (Ko-Wei Lih, Zentralblatt MATH, Vol. 1239, 2012)
“This is an introductory book that deals with the subject of extremal combinatorics. … The book is nicely written and the author has included many elegant and beautiful proofs. The book contains many interesting exercises that will stimulate the motivated reader to get a better understanding of this area. … author’s goal of writing a self-contained book that is more or less up to date … and that is accessible to graduate and motivated undergraduate students in mathematics and computer science, has been successfully achieved.” (Sebastian M. Cioaba(, Mathematical Reviews, January, 2013)