Appropriate for one- or two-semester, junior- to senior-level combinatorics courses. This trusted best-seller covers the key combinatorial ideas–including the pigeon-hole principle, counting techniques, permutations and combinations, Pólya counting, binomial coefficients, inclusion-exclusion principle, generating functions and recurrence relations, combinatortial structures (matchings, designs, graphs), and flows in networks. The Fifth Edition incorporates feedback from users to the exposition throughout and adds a wealth of new exercises.

Table of Contents:
1. What is Combinatorics? 1.1 Example: Perfect Covers of Chessboards 1.2 Example: Magic Squares 1.3 Example: The Four-Color Problem 1.4 Example: The Problem of the 36 Officers 1.5 Example: Shortest-Route Problem 1.6 Example: Mutually Overlapping Circles 1.7 Example: The Game of Nim   2. The Pigeonhole Principle 2.1 Pigeonhole Principle: Simple Form 2.2 Pigeonhole Principle: Strong Form 2.3 A Theorem of Ramsay   3. Permutations and Combinations 3.1 Four Basic Counting Principles 3.2 Permutations of Sets 3.3 Combinations of Sets 3.4 Permutations of Multisets 3.5 Combinations of Multisets 3.6 Finite Probability   4. Generating Permutations and Combinations 4.1 Generating Permutations 4.2 Inversions in Permutations 4.3 Generating Combinations 4.4 Generating r-Combinations 4.5 Partial Orders and Equivalence Relations   5. The Binomial Coefficients 5.1 Pascal's Formula 5.2 The Binomial Theorem 5.3 Unimodality of Binomial Coefficients 5.4 The Multinomial Theorem 5.5 Newton's Binomial Theorem 5.6 More on Partially Ordered Sets   6. The Inclusion-Exclusion Principle and Applications 6.1 The Inclusion-Exclusion Principle 6.2 Combinations with Repetition 6.3 Derangements 6.4 Permutations with Forbidden Positions 6.5 Another Forbidden Position Problem 6.6 Möbius Inversion   7. Recurrence Relations and Generating Functions 7.1 Some Number Sequences 7.2 Generating Functions 7.3 Exponential Generating Functions 7.4 Solving Linear Homogeneous Recurrence Relations 7.5 Nonhomogeneous Recurrence Relations 7.6 A Geometry Example   8. Special Counting Sequences 8.1 Catalan Numbers 8.2 Difference Sequences and Stirling Numbers 8.3 Partition Numbers 8.4 A Geometric Problem 8.5 Lattice Paths and Schröder Numbers   9. Systems of Distinct Representatives 9.1 General Problem Formulation 9.2 Existence of SDRs 9.3 Stable Marriages   10. Combinatorial Designs 10.1 Modular Arithmetic 10.2 Block Designs 10.3 Steiner Triple Systems 10.4 Latin Squares   11. Introduction to Graph Theory 11.1 Basic Properties 11.2 Eulerian Trails 11.3 Hamilton Paths and Cycles 11.4 Bipartite Multigraphs 11.5 Trees 11.6 The Shannon Switching Game 11.7 More on Trees   12. More on Graph Theory 12.1 Chromatic Number 12.2 Plane and Planar Graphs 12.3 A 5-color Theorem 12.4 Independence Number and Clique Number 12.5 Matching Number 12.6 Connectivity   13. Digraphs and Networks 13.1 Digraphs 13.2 Networks 13.3 Matching in Bipartite Graphs Revisited   14. Pólya Counting 14.1 Permutation and Symmetry Groups 14.2 Burnside's Theorem 14.3 Pólya's Counting formula