A primer in combinatorics Frontmatter Preface to the second edition Preface to the first edition Contents Part I: Introductory combinatorics and graph theory 1 Basic counting 2 Basic graph theory 3 Hierarchical clustering and dendrogram graphs Part II: Combinatorial analysis 4 Enumerative combinatorics 5 Existence theorems in combinatorics 6 Secondary structures of the RNA Answers solutions to selected problems Bibliography Index The second edition of this well received textbook is devoted to Combinatorics and Graph Theory which are cornerstones of Discrete Mathematics. Every section begins with simple model problems. Following their detailed analysis the reader is led through the derivation of definitions concepts and methods for solving typical problems. Theorems then are formulated proved and illustrated by more problems of increasing difficulty