Introductory Combinatorics emphasizes combinatorial ideas, including the pigeon-hole principle, counting techniques, permutations and combinations, Polya counting, binomial coefficients, inclusion-exclusion principle, generating functions and recurrence relations, and combinatortial structures (matchings, designs, graphs). Written to be entertaining and readable, this book's lively style reflects the author's joy for teaching the subject. It presents an excellent treatment of Polya's Counting Theorem that doesn't assume the student is familiar with group theory. It also includes problems that offer good practice of the principles it presents. The third edition of Introductory Combinatorics has been updated to include new material on partially ordered sets, Dilworth's Theorem, partitions of integers and generating functions. In addition, the chapters on graph theory have been completely revised. A valuable book for any reader interested in learning more about combinatorics.
For the most part I found it to be very boring and not as useful as I hoped. I found myself constantly having to go to outside sources to do effective studying, which I normally do anyway; but instead of the outside sources being supplementary to the text, they had become primary over the text.
This was required for a course. Pretty good introductory text, and the book did a good job of explaining topics when they needed expanding upon, and keeping a decent pace in general.