AMS301.01 Finite Mathematical Structures, Spring 2009

Ning SUN   nsun@ams.sunysb.edu

Syllabus                  Schedule                Lecture Notes with Animations              Homework                  Exam

 Syllabus

Course website: http://www.ams.sunysb.edu/~nsun/Teaching/ams301_spring2009.html

Class Time & Location: MoWeFr 9:35-10:30AM @SB Union 123

Office Hour: Mo 11:00AM-1:00 PM@ Math Tower B-148 (7)

Direction to my office (My room is difficult to find...): Enter the math tower, take the elevator to Floor 2, make a right, you will see red stairs. Go upstairs, make a left, you will see Room B-148. Enter the door and take a right. I'm in room #7 of B-148. 

TA 

     John La Greca   johnlagreca@gmail.com

     Office Hour: We 1-2pm@ Harriman Help Room 010

     

Textbook: Applied Combinatorics, 5th Ed., by Alan Tucker.

                   (The text part of the this version is similar with the older one, but the problem sets might be different)

Prerequisites: AMS 210 or MAT 211 or MAT 303 or AMS 361.

 

Course outline:

Graph Theory

            Basic definitions, models, isomorphism

Planar graphs, Euler, Hamilton circuits, coloring

Trees/enumeration

Shortest paths, minimum spanning trees, traveling salesperson

Enumeration and Counting

Basic counting principles; Arrangements and selections

Binomial coefficients, permutations, combinations

Generating functions

Recurrence relations/Divide and conquer

Inclusion-Exclusion formulas

 

Homeworks: Homework will be assigned weekly (approximately), and will be due at the beginning of class on the due date (before 10am). There will be approximately 10 homework sets, equally weighted, and I will drop the lowest two scores before computing your average.

No late homework will be accepted. You are allowed to collaborate on assignments with others but don’t turn in identical solutions unless the textbook shows as a guide. Please make certain that your writing is neat and clear, and that you have expressed your reasoning, not just the final answer. Please staple!

 

Exams: There will be three exams. The first two midterms will be in class, tentatively, Friday February 27, and Friday April 3 (right before spring break). The third exam (final) is Friday May 15, 11:00-1:30, and is non cumulative. All exams are closed notes and book; however, you will be allowed a cheat sheet. No calculators are allowed.

 

Grading Policy: Your grade will be based on: Homework (15%) + in-class test (35%) +Final (50%). No collaboration is allowed in any test. Violation of these collaboration rules will result in a “Fail” in this course.

 

Disability Policy: If you have a physical, psychological, medical or learning disability that may impact your course work, please contact Disability Support Services, ECC (Educational Communications Center) Building, room 128, (631) 632-6748. They will determine with you what accommodations are necessary and appropriate. All information and documentation is confidential. Students who require assistance during emergency evacuation are encouraged to discuss their needs with their professors and Disability Support Services. For procedures and information, go to the following web site: http://www.sunysb.edu/ehs/fire/disabilities.shtml


Lecture Notes with Animations (pps format)

I made a lot of animations in my PowerPoint slides. Here you can access to and play with the pps files for a better understanding of the definitions and problem solving procedures. Also in case you cannot come to the class, you won't miss the fun. 

I used PowerPoint 2007 to create all the files. However, I can open them with PowerPoint 2002. If you cannot see them, email me, or skip this part and go straight to "Schedule" part for the pdf files. 

When you use IE to access to this page and try to open or save the following files, IE might recognize them as "zip" files. So in case you are using IE, please change the extension name to ".ppsx" files and then you can use PowerPoint to open them. You can avoid those troubles by using FireFox.

Lecture 2
Lecture 3
Lecture 4
Lecture 5
Lecture 6
Prüfer Sequences
Lecture 7
Lecture 8
Lecture 9
Lecture 10
Lecture 11
Lecture 12
Lecture 13
Lecture 16
Lecture 17
Lecture 18
Lecture 19
Lecture 20
Lecture 21
Lecture 22



Schedule

1st week (Jan 26 - 30) 1.1  1.2  1.3  (by Reid)  

        Leture notes by Reid  
        Examples

2nd week (Feb 2 - 6)  1.4  2.1

        Lecture 2(updated on Feb 6)- Section 1.4 Planar Graphs

         Notes: I made a mistake about the Euler's Formula. You guys are right. This formula can only be used to calculate r (# of edges) of a connected planar graph.

                    r
 is a property of a plane graph. It should be the same when you draw the same graph in different ways (Think about the case we discussed today in class).
                   Usually we don't really count r. If you want to count it, you need to draw the graph without edges crossing  (it is called a plane graph depiction). This is shown in the proof of Euler's formula on page 36.
                   You can try Figure 1.23 on page 35 to see how to count r. There are three different plane graph depictions of a same planar graph. You should get the same r, e and v.

                    And the corollary can be used to find some nonplanar graphs. If the inequality does not hold, you can tell that the graph is nonplanar. But if it does hold, you cannot conclude that the graph is planar.   

        Lecture 3 (Feb 06) - Section 2.1 Euler Cycle

3rd  week (Feb 9 - 13)  2.2 2.3 2.4

        Lecture 4 (Feb 09) - Section 2.2 Hamilton Circuit
        Lecture 5 (Feb 11) - Section 2.3 Graph Coloring
        Lecture 6 (Feb 13) - Section 2.4 Coloring Theorems

4th  week (Feb 16 - 20 )  3.1 3.2 3.3 (part)
        Lecture 7 (updated on Feb 18, typo corrected) - Section 3.1 Properties of Trees
        Lecture 8 (Feb 18) - Section 3.2 Search Trees and Spanning Trees
       
Notes:
    I won't ask you to solve a problem like the "Balance Puzzle"(3.1) or "Pitcher- Pouring Puzzle" (3.2)  in the book. The reason I show you those fancy and tricky cases is to let you know how to model or represent a problem with a graph, especially with a tree. Just make sure you understand the procedure. (That's why I upload those lecture notes with animations).
    The purpose of the first part (before midterm 1) is to introduce some basic definitions and terminology, and famous algorithms and applications of graph theory. Don't let those "puzzles" really puzzle you. Focus on the basic stuffs, like the "True or False" exercises in Lecture 6. I do think you can see the homeworks get my idea. 

5th  week (Feb 23 - 27 ) 3.3 + 4.1 + 4.2 + review + exam 1
        Lecture 9 (Feb 23)         
        Reference: Dijkstra's Algorithm by Prof. Esther Arkin (Feb 23)


6th  week (Mar 4 - 6 ) exam anslysis + MST + 5.1
        Lecture 10 (Mar 6)     

7th  week (Mar 9 - 13 ) 5.2  5.3
        Lecture 11 (Mar 9, 11) 
        Lecture 12 (Mar 11, 13)

8th  week (Mar 16 - 20 ) 5.4  5.5
       Lecture 13 (Mar 16, 18)
       Lecture 14 (Mar 20)
       Lecture 15 (Mar 20)

9th  week (Mar 23 - 27 ) 6.1  6.2
       Lecture 16 (Mar 25)
       Lecture 17 (Mar 27)

10th week (Mar 30 - Apr 3 ) review + sample exam + exam 2

11th week (Apr 6 - 10)  spring break -- no class
        Enjoy!

12th week (Apr 13 - 17)  exam analysis + 7.1
       Lecture 18 (updated on Apr 17)  
       Animations of  "Tower of Hanoi":    n=3     n=4

13th week (Apr 20 - 24)   7.1 7.2 
       Lecture 19 (Apr 21)

14th week (Apr 27 - May 1)   8.1 8.2
       Lecture 20 (Apr 27)
       Lecture 21 (Apr 29)

15th week (Apr 27 - May 1)   8.3 + review
       Lecture 22 (May 4)
     
Homework

Solutions:
          Solution to hw1
          Solution to hw2
          Solution to hw3
          Solution to hw4
          Solution to hw5
          Solution to hw6          
          Solution to hw7      
          Solution to hw8      
          Solution to hw9      



Assignments:

HW9 (due on Friday, May 1)  covering 8.1, 8.2
          8.1: 10, 12, 20, 24, 26, 29, 36; 8.22, 6, 8

HW8 (due on Friday, Apr 24)  covering 7.1, 7.2
          7.1: 2, 4, 6 (a,b), 10, 12, 18, 28, 30; 7.28 (a,b)
Note:
7.1#4: Only think about the case in which the n miles will be finished at the end of the last hour's walking/jogging/running. The total # of hours should be an integer.
7.2#8: (c) is not required.

HW7 (due on Wednesday, Apr 1)  covering 6.1, 6.2
          6.1: 2 (b,e), 4 (b,c,d), 8, 10, 16; 6.22, 8, 18, 20

HW6 (due on Wednesday, Mar 25 )  covering 5.2, 5.3, 5.4
          5.2: 22, 34, 42;  5.3: 23; 5.42, 7, 12, 20, 27, 34, 48
Note:
5.4#48: The three conditions should be satisfied simultaneously

HW5 (updated on Mar 13, due on Wednesday, Mar 18 )  covering 5.1, 5.2, 5.3
          5.1: 6, 18, 22, 32; 5.2: 4, 10, 14, 16 (b, c, d) , 25, 32, 38; 5.312, 16 (it's too complicated),22, 26
Note:

5.1#18 (b): You don't know the total number of letters and digits you need to choose for the plate. But on the plate, you should put the letters (1, 2 or 3) consecutively. For example, 5k, 5mm4, 54mm are all possible chooses. As you learned in class, when dealing with a "consecutive grouping" of some items, you need to glue the items together. Here the difficulty is: you don't exactly know what to glue together. So do it in two stages: Find the letters first (three cases: 1, 2 or 3 letters); then glue them together as a composite letter L, choose the digits and order them. (For example, you choose 1 digit, you can have dL or Ld; when you choose 2 digits, you can have ddL, dLd or Ldd,...)

5.3#12: Split the pool into two sets: red+white+blue; 1 pink+1 lavender+1 tan. Pick k balls from the second set first (k=0, 1, 2, 3), then pick the remaining (8-k) balls from the first set. For example, you choose 1 ball from 1 pink+1 lavender+1 tan (how many ways in this stage??), and then you choose 7 balls from red+white+blue (choosing 7 from 3 types).

5.3#16: too complicated. So you don't need to do it in the hw. I will talk about it on Monday.

5.3#26(b): Since the order matters, you need to label the 9 rings: #1, #2... #9. Then think about the "brain teaser" we did in class, in which I used "x" for ice cream and "s" to differentiate the flavors. Try to interpret this question in a similar way: use numbers for rings and "s" to differentiate the fingers.  Then you can get a sequence to represent one arrangement, the there is a 1-to-1 correspondence between the arrangements and such sequences. For example, 1234s79s6s58 represents a possible arrangement: you put #1, #2, #3 and #4 rings on your index finger, #7 and #9 on your middle finger, #6 on your ring finger, and #5, #8 on your little finger. Then you calculate how many possible sequences you can have.  Note that ring #1- # 9 are different. So in total you have 10 types of items (1, 2... 9 and "s").

         


HW4 (due on Wednesday, Feb 25 )  covering 3.1, 3.2, the approximate traveling salesperson tour construction in 3.3
          hw4 (updated on Feb 23)

Note:  In question 4: The rightmost vertex in the bottom is E, the leftmost is F. Probably you cannot see the difference in the original version.
          In question 7: Each main diagonal entry should be infinity instead of zero.           

Note: #8 is not required. It covers the shortest path (Dijkstra’s Algorithm) in 4.1, and MST (Kruskal’s algorithm and Prim’s algorithm) in 4.2, which I will talk about after the exam 1. This part is very important in operation research, but won’t be covered by any exam in our class. So if you’re interested, you can do it for fun.
         

HW3 (due on Wednesday, Feb 18 )  covering 2.2, 2.3 2.4
          2.2: 4 (f, h,  l); 2.31(l,n), 2(b,e), 12; 2.44, 5
Hints:
          In 2.2: 12, when you are asked to model the problem as a graph-coloring problem, you need to state what the vertices and edges correspond to, and what the goal of the problem (for example, you want to find the chromatic number or edge chromatic number).



HW2 (due on Friday, Feb 13 )  covering 1.4, 2.1
          1.4: 3 (f, j), 4, 7 (f,  i), 16; 2.1: 2, 4(Figure 1.4 in on page 6 or page 8. In the question,  no edges can be drawn more than once)
Hints:
          In 1.4: 4, the "infinite region" refers to the region outside the graph. So try to make the circuit bounds your whole graph, then the outside region is bounded by this circuit. 
          In 2.1: 2: Kr,s is a bipartite graph in which there are two groups of vertices. Group1 has r vertices, each of which connects with all the vertices in Group 2. Group 2 has s  vertices, each of which connects with all the vertices in Group 1. K3,3 is the specical case of Kr,s.



HW1 (due on Monday, Feb 9)  covering 1.1, 1.2, 1.3
          1.1: 2, 4, 16, 23; 1.2: 4, 5 (b c k ), 6 (a, e, f); 1.3: 4,8         
Hints:  
        In 1.1: 2 and 4, when you represent the relationship witha graph, make sure to state what the vertices correspond to and what the edges correspond to.
        In 1.2: 5 and 6, when determine whether two graphs are isomorphic, you need to explain: if they are isomorphic, show the 1-to-1 correspondence; if they are not, show the difference between two graphs.
        In 1.3: 4, notice that in a complete graph Kn, all the vertices have degree (n-1). Think about the definition and relationship of Kn, G, and the complement of G.





Exam

Final     (11:00am - 1:00 pm, May 15) covering Chapter 7(7.1-7.2), 8 (8.1-8.3)
             closed notes and book, no calculators
             a cheat sheet allowed (4 by 6 index card, written by hand, 2-sided)             

             Exam3 sample
             Solution to sample3   

             Final  
             Solution to Final
   

            Summary: # took exam - 50/52, highest - 100 (1 of 50), lowest - 5, mean - 65, median - 71
                             The stem and leaf plot:
                                0 | 5
                                1 |
                                2 | 2267
                                3 | 0
                                4 | 88999
                                5 | 1144789
                                6 | 222789
                                7 | 0111234456799
                                8 | 0124566679
                                9 | 27
                              10 | 0                             

Exam 2 (Friday, Apr 3) covering Chapter 5(5.1-5.4), 6 (6.1 6.2)
             in class, closed notes and book, no calculators
             a cheat sheet allowed (4 by 6 index card, written by hand, 2-sided)             

             Exam2 sample  
             Solution to sample2
   

             Exam2  
             Solution to Exam2
   

          Summary: # took exam - 49/52, highest - 115 (11 students got higher than 100), lowest - 37, mean - 80, median - 82

Note:

The seven questions in the sample are not equally weighted. The last two questions are more complicated than the first five. So you can get some extra credit by choosing them.
In the real exam 2, you will have a similar problem set with the two-question "bonus". Please pay attention to the time. The highest score can be 115. 

Exam 1 (Friday, Feb 27) covering Chapter 1, 2, 3 (3.1-3.3)
             in class, closed notes and book, no calculators
             a cheat sheet allowed (4 by 6 index card, written by hand, 2-sided)
             Exam1 sample  
             Solution to sample1 

             Exam1 (word,  pdf )
            Solution to exam1 (updated on Mar 1)

            Summary: # took exam - 50/52, highest - 100 (13 of 50!!!), lowest - 27, mean - 84, median - 93
            See the updated solution to find some comments on the common errors.
            It seems easy for most of the class.


updated by Ning SUN on May 16, 2009