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Combinatorics
Combinatorics is an upper-level introductory course in enumeration, graph theory, and design theory. The text focuses on combinations and arrangements of discrete structures. There are five major branches of combinatorics that we will touch on in this course: enumeration, graph theory, Ramsey Theory, design theory, and coding theory. We will focus on enumeration, graph theory, and design theory, but will briefly introduce the other two topics.
- Author
- Joy Morris
- Publisher
- University of Lethbridge
- Source
- LibreTexts
- License
- CC BY-NC-SA
- Language
- EN
- Category
- Basic Sciences
Contents· 103 sections
- 01: Introduction
- 01: What is Combinatorics
- 1.01: Enumeration
- 1.02: Graph Theory
- 1.03: Ramsey Theory
- 1.04: Design Theory
- 1.05: Coding Theory
- 1.06: Summary
- 02: Enumeration
- 02: Basic Counting Techniques
- 2.01: The Product Rule
- 2.02: The Sum Rule
- 2.03: Putting Them Together
- 2.04: Summing Up
- 2.05: Summary
- 03: Permutations Combinations and the Binomial Theorem
- 3.01: Permutations
- 3.02: Combinations
- 3.03: The Binomial Theorem
- 3.04: Summary
- 04: Bijections and Combinatorial Proofs
- 4.01: Counting via Bijections
- 4.02: Combinatorial Proofs
- 4.03: Summary
- 05: Counting with Repetitions
- 5.01: Unlimited Repetition
- 5.02: Sorting a Set that Contains Repetition
- 5.03: Summary
- 06: Induction and Recursion
- 6.01: Recursively-Defined Sequences
- 6.02: Basic Induction
- 6.03: More Advanced Induction
- 6.04: Summary
- 07: Generating Functions
- 7.01: What is a Generating Function
- 7.02: The Generalized Binomial Theorem
- 7.03: Using Generating Functions To Count Things
- 7.04: Summary
- 08: Generating Functions and Recursion
- 8.01: Partial Fractions
- 8.02: Factoring Polynomials
- 8.03: Using Generating Functions to Solve Recursively-Defined Sequences
- 8.04: Summary
- 09: Some Important Recursively-Defined Sequences
- 9.01: Derangements
- 9.02: Catalan Numbers
- 9.03: Bell Numbers and Exponential Generating Functions
- 9.04: Summary
- 10: Other Basic Counting Techniques
- 10.01: The Pigeonhole Principle
- 10.02: Inclusion-Exclusion
- 10.03: Summary
- 03: Graph Theory
- 11: Basics of Graph Theory
- 11.01: Background
- 11.02: Basic Definitions Terminology and Notation
- 11.03: Deletion Complete Graphs and the Handshaking Lemma
- 11.04: Graph Isomorphisms
- 11.05: Summary
- 12: Moving Through Graphs
- 12.01: Directed Graphs
- 12.02: Walks and Connectedness
- 12.03: Paths and Cycles
- 12.04: Trees
- 12.05: Summary
- 13: Euler and Hamilton
- 13.01: Euler Tours and Trails
- 13.02: Hamilton Paths and Cycles
- 13.03: Summary
- 14: Graph Coloring
- 14.01: Edge Coloring
- 14.02: Ramsey Theory
- 14.03: Vertex Colouring
- 14.04: Summary
- 15: Planar Graphs
- 15.01: Planar Graphs
- 15.02: Eulers Formula
- 15.03: Map Colouring
- 15.04: Summary
- 04: Design Theory
- 16: Latin Squares
- 16.01: Latin Squares and Sudokus
- 16.02: Mutually Orthogonal Latin Squares (MOLS)
- 16.03: Systems of Distinct Representatives
- 16.04: Summary
- 17: Designs
- 17.01: Balanced Incomplete Block Designs (BIBD)
- 17.02: Constructing Designs and Existence of Designs
- 17.03: Fishers Inequality
- 17.04: Summary
- 18: More Designs
- 18.01: Steiner and Kirkman Triple Systems
- 18.02: t-Designs
- 18.03: Affine Planes
- 18.04: Projective Planes
- 18.05: Summary
- 19: Designs and Codes
- 19.01: Introduction
- 19.02: Error-Correcting Codes
- 19.03: Using the Generator Matrix For Encoding
- 19.04: Using the Parity-Check Matrix For Decoding
- 19.05: Codes From Designs
- 19.06: Summary