CSC 201 - Discrete Mathematics for Computer Scientists

Shai Simonson    226 College Center    (508) 565-1008



Lectures:  MWF  9:30 - 10:20,   215 College Center

Text:  Discrete Mathematics and its Applications, Rosen, McGraw Hill, 8th edition.

Exams:  There will be six quizzes and I will count the top five (25%).  There is one final examination (35%). The final will be Wednesday, December 18, 9:00 AM.

Teaching Assistant:  Vlod.  Help sessions every Sunday night 5:30 -7:00 PM in the lab.

Assignments:  Homework assignments will be worth 40% of your grade.  You may do these with a partner, and one grade will be given to both people in each group, but you may work alone if you prefer to do so.  Read our department's academic integrity guidelines before you hand in any written work

Grading:  Your grade is 25% quizzes, 40% homework, and 35% final  exam.  You can guarantee an A- or better with 90%, a B- or better with 80% etc.  I may curve these numbers in your favor, if I feel it is warranted.

Goals:  To understand the mathematics that underlies computer science, and to appreciate where it is used.  This semester will concentrate on functions, number theory, recurrence equations, recursion, combinatorics, and their applications.  Next semester concentrates on sets, Boolean algebra, linear algebra, and their applications.  

Special Dates:   September 30, October 9, and October 21 are Jewish holidays. Instead of lecture, there will be a quiz or a TA homework review. I will announce details in class.

Description:   The two-semester discrete math sequence covers the mathematical topics most directly related to computer science. Topics include: logic, relations, functions, basic set theory, countability and counting arguments, proof techniques, mathematical induction, graph theory, combinatorics, discrete probability, recursion, recurrence relations, linear algebra, and number theory.  Emphasis will be placed on providing a context for the application of the mathematics within computer science. The analysis of algorithms requires the ability to count the number of operations in an algorithm. Recursive algorithms in particular depend on the solution to a recurrence equation, and a proof of correctness by mathematical induction. The design of a digital circuit requires the knowledge of Boolean algebra.  Software engineering uses sets, graphs, trees and other data structures. Number theory is at the heart of secure messaging systems and cryptography. Logic is used in AI research in theorem proving and in database query systems. Proofs by induction and the more general notions of mathematical proof are ubiquitous in theory of computation, compiler design and formal grammars. Probabilistic notions crop up in architectural trade-offs in hardware design.  Linear algebra has a vast variety of applications including:  Markov chains, cryptography,  computer graphics, curve fitting, electrical circuits, and data mining.  The first semester concentrates on induction, proofs, combinatorics, recurrence relations, computational complexity, Big-O, and number theory.  The second semester concentrates on logic, sets, set algebra, functions, countability, Boolean algebra, linear algebra and applications.


Useful Links

Rosen Online Help       Cut-the-Knot        Math in CS         My Video Lectures      Wolfram Alpha

Reading and Other Assignments

Written Assignments

Note:  These are long assignments so you should spread your efforts over a period of 2-3 weeks for each one;  you will learn more and get better grades if you do.  I will review any question before we start class on any day, and I will give hints and guide you.  Never give up.

Assignment 2 Assignment 3 Assignment 4

Brief Syllabus

Week Topics Reading
1 What kinds of problems are solved in discrete math? What are proofs? Examples of proofs by contradiction, constructive proofs, and proofs by induction: Triangle numbers, irrational numbers, and prime numbers. 1.7-1.8, 5.1
2 Primes, Greatest Common Divisors and the Euclidean Algorithm.   Binary numbers and conversions from binary to decimal and vice versa.  The Egyptian fast-exponentiation algorithm.  The two-jug puzzle as demonstrated by Bruce Willis in Die Hard III.  Congruences and Fermat’s Little theorem. Applications to Cryptography.  4.1-4.6
3 More mathematical induction.  Tips for induction proofs - thinking forwards and backwards.  Many examples and the idea of strong induction. 5.1-5.2
4 Basic arithmetic and geometric sums, closed forms. Growth rate of functions, Big-O notation. Applications to algorithms. 2.3-2.4, 3.1-3.3
5 Recursion and solving recurrence equations by repeated substitution:  Compound Interest, Binary search, Insertion Sort, Merge Sort. 
Towers of Hanoi –  graphs as a visual tool. 
6 Recursion and solving recurrence equations by repeated substitution:  Chinese rings puzzle – Grey codes, change of variable technique. Pages 702-703.
7-8 Solving recurrence equations:  Master Theorem with applications to algorithms.
Guessing and proving correct by induction - The Josephus Problem, and the kth largest problem
8.1, 8.3
9 Solving recurrence equations – Linear homogeneous equations, linear non-homogeneous equations. 8.2
10 Combinations and permutations. Pascal’s triangle and binomial coefficients.  6.1, 6.3-6.4
11 Counting problems using combinations, distributions and permutations. 6.5-6.6
12 Sets.  The inclusion/exclusion theorem and advanced examples. 2.1-2.2, 8.5-8.6
13 The pigeonhole principle and examples.  6.2
14 Discrete probability, the birthday paradox, conditional probability, expected value, and many examples.  7.1-7.4
15 Review