1. Data Structures, Algorithms, & Applications
Richard Newman
(based on course by Sartaj Sahni)

2. Clip Art Sources www.barrysclipart.com www.livinggraphics.com

3. What The Course Is About
Data structures : representation and manipulation of data.
All programs manipulate data.
So all programs represent data
Data manipulation requires an algorithm.
Data: Streets in a city. Mapquest.
Manipulation: Do something with the data. Add a new street. Close a street. Make a street one way. Find route from your home to nearest gas station. Input/output data.
Data representation: simple variables…int, float
array variables… int [], float []
Others to be studied in this course.
Algorithm…sequence of steps that results in the performance of a specific task (find nearest gas station to home).

4. What The Course Is About
Algorithm design methods needed to develop programs that do the data manipulation.
The study of data structures and algorithms is fundamental to Computer Science.
What we do in this course will be used in most of the follow-up courses you will take. Essential to become expert in what we do this semester. Else, you will be handicapped in later courses.

5. Prerequisites Java Asymptotic Complexity
Big Oh, Theta, and Omega notations
Java review … Chapter 1
Performance Analysis … Chapter 2
Asymptotic complexity … Chapter 3

6. Web Site
Handouts, syllabus, text, source codes, exercise solutions, lectures, assignments, past exams, past exam solutions, TAs, etc.
Check twice weekly (48 hr apart)

7. Assignments Assignment guidelines Submission procedures
Do Assignment 0 by next Friday.
Must follow guidelines and submission procedures. Else there will be chaos.
Submit jar files via CourseWorX night before class, hardcopy in class.
Design and code documentation required for TA to assist in debugging.

8. Source Codes Read download and use instructions.
Must have Java 1.2 or higher.
See ProgramIndex.htm, AllNames.html and other html files produced by Javadoc for Java codes.

9. Discussion Sections Go to any one TA will answer your questions
TA will go through a few exercises from the book
Web site lists what is done in each meeting of the discussion section
M 8,9 T 8,9,11 – all in CSE-221
W 3 – in TUR 2346

10. Organization of Text Three parts Part I … Chapters 1-4, Background
Part 2 … Chapters 5-17, Data Structures
Part 3 … Chapters 18-22, Algorithms
Each chapter … concepts + applications

11. Grades 25% for assignments 25% for each test (3 exams) Exam 1 – Feb 15
Exam 2 – Mar 31
Exam 3 – Apr 29 7:30 am

12. Grades (Rough Cutoffs)
B+ >= 75%
B >= 70%
C+ >= 65%
C >= 60%
D+ >= 55%
D >= 50%

13. Classic Problem: Sorting
Rearrange a[0], a[1], …, a[n-1] into ascending order. When done, a[0] <= a[1] <= … <= a[n-1]
8, 6, 9, 4, 3 => 3, 4, 6, 8, 9
Strictly speaking, nondecreasing order: 2, 2, 3, 6, 8, 8, 10.

14. Sort Methods Insertion Sort Bubble Sort Selection Sort Count Sort
Shaker Sort
Shell Sort
Heap Sort
Merge Sort
Quick Sort
First 5 are simple (conceptually and to program). First 4 done in chapters 2 and 3. Shaker sort and shell sort are in the enrichment section of the text’s Web site. The remaining three are done in the algorithm design chapters of the text.

15. Insert An Element Given a sorted list/sequence, insert a new element
Result 3, 5, 6, 9, 14

16. Insert an Element 3, 6, 9, 14 insert 5
Compare new element (5) and last one (14)
Shift 14 right to get 3, 6, 9, , 14
Shift 9 right to get 3, 6, , 9, 14
Shift 6 right to get 3, , 6, 9, 14
Insert 5 to get 3, 5, 6, 9, 14

17. Insert An Element // insert t into a[0:i-1] int j;
for (j = i - 1; j >= 0 && t < a[j]; j--)
a[j + 1] = a[j];
a[j + 1] = t;

18. Insertion Sort Start with a sequence of size 1
Repeatedly insert remaining elements

19. Insertion Sort Sort 7, 3, 5, 6, 1 Start with 7 and insert 3 => 3, 7

20. Insertion Sort for (int i = 1; i < a.length; i++)
{// insert a[i] into a[0:i-1]
// code to insert comes here }
Top-down approach to program development – pseudocode in comments

21. Insertion Sort for (int i = 1; i < a.length; i++)
{// insert a[i] into a[0:i-1]
int t = a[i];
int j;
for (j = i - 1; j >= 0 && t < a[j]; j--)
a[j + 1] = a[j];
a[j + 1] = t; }
Turn pseudocode into code.

22. Correctness Program verification Testing Debugging
Mathematical (logical) correctness
Cleanroom development
Testing
Black box
White (clear) box
Debugging
Strategies

23. Next – Lecture 2
Read 3.5
Complexity of insertion sort