1. Chapter 8 Data Abstractions Introduction to CS 1 st Semester, 2015 Sanghyun Park

2. Outline  Data Structure Basics  Arrays  Lists  Stacks  Queues  Trees

3. Data Structure Basics  The topic of data structures explores ways in which users can be ________ from the details of actual data storage (__________)  The shape or size of data structures may or may not change over time (dynamic vs. static structures); ____ structures are easier to manage than dynamic ones  A ______ is a memory cell that contains the address of another memory cell; the value in the pointer tells us where to find the data

4. Single Dimensional Arrays  If the first reading is at address x, the i th reading is located at address ________

5. Two Dimensional Arrays  Row major order vs. column major order  If we let c represent the number of columns in an array, then the address of the entry in the i th row and j th column will be ________________ x

6. Contiguous Lists  List is a collection of entries that appear in a _____ order  Lists appear in both static and dynamic forms  Let us consider techniques for storing a list of names in a machine’s main memory  The simplest structure is a ___________ list

7. Linked Lists  A contiguous list suffers disadvantages when implementing ________ lists  The problem encountered can be simplified if we use _______ lists

8. Deleting an Entry From Linked List

9. Inserting an Entry Into Linked List

10. Supporting The Conceptual List  To support the ________ to the list structure, the programmer should write a collection of __________ for performing such activities as inserting a new entry and searching for an entry  The users do not concern whether the list structure is implemented as a contiguous structure or a linked one; the users only call the procedure like PrintList(CSI2106)

11. Stacks  A _____ is a list in which all insertions and deletions are performed at the _____ end of the structure  The last entry entered will always be the first entry removed – last-in, first-out (______) structure  The end of a stack at which entries are inserted and deleted are called the ____ of the stack  The process of inserting an entry on the stack is called a ____ operation, and the process of deleting an entry is called a ____ operation

12. Backtracking  A classic application of a stack occurs when a program unit requests the execution of a ________  As each procedure is called, a ______ to the return location is pushed on a stack; as each procedure is completed, the top entry from the stack is extracted

13. Printing a Linked List in Reverse Order (1/3)

14. Printing a Linked List in Reverse Order (2/3)

15. Printing a Linked List in Reverse Order (3/3)

16. Stack Implementation  Push operation needs a test if stack is ____  Pop operation needs a test if stack is _____

17. Queues  A _____ is a list in which all insertions are performed at ____ end while all deletions are made at the ____ end  The concept of a queue is inherent in any system in which objects are served in the same order in which they arrive - first-in, first-out (_____) structure  The end at which entries are removed is called the ____  The end at which new entries are added is called the ___

18. Queue Implementation

19. Queue “Crawling” Through Memory

20. Circular Queue

21. An Example of an Organization Chart

22. Representation of a Tree

23. Tree Terminology

24. Binary Trees  Binary trees are trees in which each node has at most ___ children  Such trees normally are stored in memory using a ______ structure similar to that of linked lists

25. Examples of Binary Trees

26. A Binary Tree Using a Linked Storage System

27. A Binary Tree Stored Without Pointers

28. A Sparse Binary Tree Stored Without Pointers

29. Binary Search Using Binary Trees

30. Binary Search Example

31. Depth-First Traversal

32. Preorder Traversal

33. Inorder Traversal

34. Postorder Traversal

35. Breadth-First Traversal