CIS 2420 Data Structures

1. CIS 2420 Data Structures

2. Course Objectives and Methods: • Students will acquire the skill of designing and implementing abstract data structures in a high-level programming language. • CIS*242 will convey the concept of layered software by separating the application from the implementation using abstraction. • When building data structures students will review methods of performance and complexity analysis of algorithms used for implementation. Introduction

3. Data structures will include lists, vectors, queues, stacks, trees, dictionaries, hash-tables, and graphs. • Algorithms used include searching, sorting, text processing using the above data structures. • On assignments, students are asked to program data structures using a high-level programming language. • On exams and quizzes, students are asked to solve problems using analytical methods and programming skills acquired from lectures and assignments to demonstrate knowledge and comprehension of course material. Introduction

4. Prerequisite(s): CIS*2650, (CIS*1900 or MATH*2000). • Text Book: M.T.Goodrich and R.Tamassia Data Structures & Algorithms in Java (2nd Edition),WILEY,1997. Introduction

5. Course Format and Schedule: Course webpage can be found at: http://www.cis.uoguelph.ca/~welazmeh/cis242/fall03 Students will attend lectures presented by the professor and lab-tutorials presented by a teaching assistant. The lectures schedule is: Tuesdays/Thursdays 08:30-09:50 MACN 105 Office hour: Email for an appointment Introduction

6. Labs Schedule: Starting Monday, Sept. 8, 2003, students must sign up for a lab section. Labs start on Sept. 15, 2003. The labs are limited to 30 students per lab section. To register in a lab section, pick a suitable time and write your ID in the registration list posted outside Reyn 321. The spaces are reserved for the first 30 students registered on that list. (please do not change groups unless approved by your instructor). Introduction

7. Course Evaluation: (1) 4 Assignments: equally weighted 5% 20% (2) 2 Quizzes: weighted 15%, 15% 30% (3) Final Exam: 50% *** in order to pass the course (minimum passing grade), students MUST obtain at least 50% on the weighted average of the quizzes and final exam.Total: 100% Introduction

8. Course Topics: 1. Intro algorithm complexity analysis 2. Stacks,queues,vectors,and lists 3. Trees 4. Priority queues 5. Dictionaries and hashing 6. Search trees 7. Sorting 8. Text Processing 9. Graphs Introduction

9. Instructor Information: Prof. Xining Li xli@snowhite.cis.uoguelph.ca Thornbrough Bkdg 1389 Ext: 56548 Prof. William Elazmeh welazmeh@cis.uoguelph.ca Reynolds 321 Ext: 58762 Introduction

10. Important Dates: Tuesday 09/09/2003: Classes begin Monday 29/9/2003: Assignment #1 Due Monday 13/10/2003: Assignment #2 Due Thursday 16/10/2003: Quiz #1 (in class) Monday 03/11/2003: Course Drop Deadline Monday 03/11/2003: Assignment #3 Due Thursday 20/11/2003: Quiz #2 (in class) Monday 24/11/2003: Assignment #4 Due Friday 28/11/2003: Last Day of Class Wednesday 03/12/2003: Final Exam Introduction

11. Important Notes: • Late assignments or labs are NOT ACCEPTED. • Missed quizes result in a mark of zero, unless (see next item). • Illness and severe circumstances may be accommodated, email your instructor at least 48 hours before the due time and provide certification whenever possible. • An excused absence from quizzes or labs is not provided to accommodate personal inconveniences and other minor problems. • Marks Posting: When ready, you may be able to examine your marks through the course webpage (the marks will be posted during the term). Introduction

12. Important Notes: • Your final grade will be based on the grading system published in the university calendar. • To appeal a mark on an assignment, a lab or a quiz, you must do so within two weeks after they are handed back. • Each assignment will indicate its due time and date. • Academic misconduct includes the submission of program code or assignment answers that appear so similar to another student's work as to be semantically indistinguishable. Misconduct cases will be handles swiftly, discreetly,and summarily by the Department in accordance with University principles. Introduction

13. Java = C++ -- • Java is a general purpose object-oriented programming with extensions to support GUI and network (client/sever) applications. • Java is architecturally neutral. It is an interpreted language. It is supported by a variety of hardware platforms and operating systems. Introduction

14. Source-level and executable-level portability: • Programs written by a high-level programming language are source-level portable (some special cases). • Source-code programs are not directly executable, they must be compiled. • A compiler could be designed to generate two types of executable code: bytecode or binarycode. • Bytecode programs are executable-level portable, they are executed by an interpreter (virtual machine, emulator ...). • Binarycode programs are not portable, they are executed by hardware. Introduction

15. Three alternatives for running Java programs: • Java interpreter. It translates Java bytecode on-the -fly. It is usually slow, sometimes at only 3-10 percent the speed of compiled C code. • JIT (Just-In-Time) compiler. It converts Java bytecode into native (binary) code. This can result in significant performance improvements, but sometimes a JIT compiler takes an unacceptable amount of time and memory to do the compilation. • Java chip. It is a dedicated Java processor, natively understand Java bytecode without the overhead of an interpreter or JIT compiler. Introduction

16. Types of Java programs: • Standalone application: main() • Applet - code executed by a web browser: no main() Introduction

17. Object-Oriented Programming: class: define state domain name: symbolic identifier Object: state: current state location: memory reference methods: pre/user defined type: defines value domain name: symbolic identifier Data: value: a specific value location: memory reference operations: predefined on basic types. Object-Oriented programming: glues data and their related operations into one piece - object. Introduction

18. Object-Oriented concepts: • Class: The fundamental structure in Java. Class = Structured_type + Associated_operations. • Inheritance: A relation between classes that allows for the definition and implementation of one class to be based on that of other existing classes. The inheritance relation is often called the “is a" relation. • Encapsulation: A language construct that enables programmers to limit access to parts of an object. • Overloading: The ability to use the same name for multiple methods. • Polymorphism: In general, polymorphism means the ability to take more than one form. In OO, it indicates the ability to deal with multiple types based on a common feature. Introduction

19. Class Modifiers: Introduction

20. Method Usage Modifiers: Introduction

21. Method Scope Modifiers: Introduction

22. Variable Modifiers, Their Scopes and Extents: There are three kinds of variables in Java: instance variables, class variables and local variables. Characteristics related with variables are types, modifiers, scopes, extents, and initial values. Introduction

23. Variable usage modifiers: Introduction

24. Variable scope modifiers: Introduction

25. Extent of a variable: Introduction

26. Declarations: • The general form of data declaration: <Modifiers> <type_name><variable_name> [= <initial_value>]; • The general form of object declaration: <Modifiers> <type_name><variable_name> [= new <costructor>]; • Object declarations (without an initialization) do not create objects. For example: Bicycle blackice; // no blackice object yet Bicycle blackice = new Bicycle(...); // create an object blackice Introduction

27. Operators and Expressions: There are factors that influence the final value of an expression: • Precedence: it says that some operations bind more tightly than others. • Associativity: it defines the tie breaker for deciding the binding when we have several operators of equal precedence strung together. • Evaluation_order: it tells the sequence (for each operator) in which the operands are evaluated. Introduction

28. The Basic Statements: • selection: if and switch statements • iteration: for, while, and do statements • control transfer: return, throw, continue, break, and goto statements • guarding: synchronized statement • method call: object.method(arg_list); Introduction

29. The Object Class: • In Java, nearly everything is an object. Every class is ultimately inherited from the ultimate superclass Object, i.e., any object obj in a Java program can be converted to an object of Object by casting (Object) obj. • Most Java utility classes require the use of instances of Object. However, variables of basic types are not instances of Object yet. • Thus Java provides a simple way to promote them when needed. Introduction

30. The class version of basic types: Introduction

31. An example of moving an int to an Integer object and an Integer to an int, using methods from the Integer class: Integer iobj; int i = 42; iobj = new Integer(i); // to Object i = iobj.intValue(); // to int Introduction

32. Interfaces: • Interfaces are skeletons of classes. They are used to specify the form that something must have, but not actually provided the implementation. • An interface only declares methods and defines constants (variables). • An interface can be implemented by any class. • A class can implement several interfaces at once. (different from inheritance, a class can only extend one parent class). • An interface is a static (compile-time) protocol. (An abstract class implies inheritance, which may select a proper method at runtime). • Any methods or variables declared in a public interface are implicitly public. • An interface may extend any number of other interfaces. Introduction

33. 1. A program written in the JavaTM programming language can run on any platform because... • A. Java programming is derived from C++. • B. The Java Virtual Machine(JVM) interprets the program for the native operating system. • C. The compiler is identical to a C++ compiler. • D. The APIs do all the work. Introduction

34. 2. An applet will run in almost any browser because... • A. The server has a built-in JVM. • B. The browser has a built-in JVM. • C. The source code is interpreted by the browser. • D. Applets don't need a JVM. Introduction

35. 3.What is the purpose of the main method? • A.To build a user interface. • B.To hold the APIs of the application. • C.To create buttons and scrollbars. • D.To act as the entry point for the program. Introduction

36. 4.The Applet class provides... • A. A browser to run the applet. • B. Methods to define the applet's behavior and appearance. • C. A special HTML page. • D. Permission to communicate with the server. Introduction

37. 5.Which method will a web browser call first on a new applet? • A. main method • B. start method. • C. init method. • D. paint method. Introduction

38. 6.What is the advantage of using import statements? • A.To avoid having to declare variables. • B.To refer to a class without using prefixes. • C.To avoid calling methods. • D.To import the images you want to use. Introduction

39. 7.When a program class implements an interface, it must provide behavior for... • A. Two methods defined in that interface. • B. Only certain methods in an interface. • C. Any methods in a class. • D. All methods defined in that interface. Introduction

40. 8.A constructor is used to... • A. Free memory. • B. Initialize a newly created object. • C. Import packages. • D. Create a JVM for applets. Introduction

41. 9.The BorderLayout class provides static fields for... • A. Introducing new methods. • B. Adding components to specific areas of a container. • C. Starting an applet. • D. Specifying font size and color. Introduction

42. 10.Servlets are typically used for... • A. Creating graphics. • B. Extending a web server by providing dynamic web content. • C. Storing information in applets. • D. Loading buttons and menus. Introduction