Title: Combinatorial Mathematics
Class: MWF 2:00 to 2:50 pm,
PSYCH 305
Problem sessions: Friday 3:00 to 4:00 pm
PSYCH 206
Instructor: Ji Li
Office: Math 319
Phone: (520) 621-6870
Email: jli at email.arizona.edu
Office Hours: MWF 1:00 to 1:50pm, and by appointments.
Syllabus (pdf)
Weekly Notice
- Week 15: May 4 thru May 8: contains information about the last week.
- Week 14: Apr 27 thru May 1: Lessons on old and new problems are covered in class. Optional take-home final exam is due on May 3.
- Week 13: Apr 20 thru Apr 24: Lessons on Graphs are covered in class. Homework 11 is due on Apr 27.
- Week 12: Apr 13 thru Apr 17: Lessons on Permutation Groups and Labeled Trees are covered in class. Homework 10 is due on Apr 20.
- Week 11: Apr 6 thru Apr 10: including Homework 9 (Sections 9.1 and 9.2) due on Apr 13.
- Week 10: Mar 30 thru Apr 3: the next homework assignment will be due on Monday, Apr 13.
- Week 9: Mar 23 thru Mar 27: including Homework 8 (Section 8.3) due on Mar 30.
- Week 8: Mar 9 thru Mar 12: including Homework 7 (Sections 8.1 and 8.2) due on Mar 23.
- Week 7: Mar 2 thru Mar 6: including Homework 6 (Sections 7.1, 7.3, and 7.5) due on Mar 9.
- Week 6: Feb 23 thru Feb 27: including Homework 5 (Section 7.1) due on Mar 2.
- Weeks 4 & 5: Feb 9 thru Feb 20: including Homework 3 (Sections 6.1 and 6.2) due on Feb 16, and Homework 4 (Section 6.4) due on Feb 23.
- Week 3: Feb 2 thru Feb 6: Exam 1 information, Review session scheduling.
- Week 2: Jan 26 thru Jan 30: including Homework 2 (Sections 5.3, 5.4 and 5.5) due on Feb 2.
- Week 1: Jan 14 thru Jan 23: including Homework 1 (Sections 5.1 and 5.2) due on Jan 26.
Lessons
- End-of-semester Lecturs
- Chapter 9
- Lesson32, Apr 20, 22, 24: Enumeration of Graphs.
- Lesson31, Apr 17: Labeled Trees, Part II.
- Lesson30, Apr 15: Labeled Trees, Part I.
- Lesson29, Apr 10, 13, 15: Cycle Index of Group Actions and Permutation Groups.
- Lesson28, Apr 8: Polya's Cycle Index: Examples (Part of Homework due on Monday, April 20).
- Lesson27, Apr 6: Weighted Version of Cauchy-Frobenius Theorem Part II, and Power Sum Symmetric Functions.
- Lesson26, Mar 30: Weighted Version of Cauchy-Frobenius Theorem Part I.
- Lesson25, Mar 27: Cauchy-Frobenius Theorem.
- Lesson24, Mar 27: Group of Symmetries.
- Lesson23, Mar 25: Group Actions.
- Chapter 8
- Lesson22, Mar 25: Rook Polynomials and Problem Manage.
- Lesson21, Mar 23: Restricted Permutations and Rook Polynomials.
- Lesson20, Mar 11: Derangements and Notations.
- Lesson19, Mar 9: Inclusion-Exclusion and Derangements.
- Lesson18, Mar 6: Venn Diagram and Inclusion-Exclusion.
- Lesson17, Mar 4: Venn Diagram.
- Chapter 7
- Chapter 6
- Lesson13, Feb 20: Composition of Exponential Generating Functions
- Lesson12, Feb 18: Exponential and Ordinary Generating Functions
- Lesson11, Feb 16: Exponential Generating Functions
- Generalized Pigionhole Principle
- Lesson10, Feb 10: from section 6.1 to 6.2: Generating Functions
- Lesson9, Feb 9: starting section 6.1: Introducing (Ordinary) Generating Functions
- Chapter 5
Exams
Puzzles and Some of the Solutions
- Puzzle 8: problem on derangements.
- Puzzle 7: problem on recurrence relations: solved by Anantha Krishnan, and Michael O'Connell.Solution
- Puzzle 6: Problem 10 on page xiv: solved by James Pohl.
- Puzzle 5: problem: solved by Anantha Krishnan.
- Puzzle 4: problem: solved by Anantha Krishnan. Solution
- Puzzle 3: Problem: solved by Dzung Nguyen.
- Puzzle 2: Problem: solved independently by James Pohl and Marcus Schmidt.
- Puzzle 1: Problem 2 on page xiii, solved by Ben Robbins. Solution.
Supplementary Handouts
- Chapter 5
- For Chapter 5: Numerical Problems: containing different counting problems for different levels.
- From Section 5.1: Arranging Books: a different approach to Example 3, and a basic idea of Inclusion-Exclusion.
Quotes
No matter what it is, there is nothing that cannot be done. If one manifests the determination, he can move heaven and earth as he pleases. But because man is pluckless, he cannot set his mind to it. Moving heaven and earth without putting forth effort is simply a matter of concentration.
Yamamoto Tsunetomo in "Shadow of the Leaves".