* Definition of ADT * Set * List * Stack * Queue * Map * Tree * Graph

1. Abstract Data Types
Reggie Santos
UP ITDC
Content mostly adapted from Mike Scott, UT Austin

2. Outline
Definition of ADT
Set
List
Stack

3. Outline
Queue
Map
Tree
Graph

4. Abstract Data Type
(ADT)
Stores data
Allows various operations on the
data to access or change it

5. Why Abstract?
Specify the operations of the data
structure and leave implementation
details for later
High-level languages often provide
built-in data structures

6. The Core
Operations
Every Collection ADT should
provide a way to:
Add an item
Remove an item
Find, retrieve, or access an item

7. Additional
Operations
More possibilities:
Is the collection empty?
Make the collection empty
Give a subset of the collection

8. –David Jones
“Get your data structures correct
first, and the rest of the program
will write itself.”

9. Program Logic Formulation

10. Image credit: Ledork via flickr Creative Commons

11. Set
Unordered collection of data items
No duplicate items are allowed

12. Image credit: pasukaru76 via flickr Creative Commons
Image credit: Stacy Spensley via flickr Creative Commons

13. List
Ordered collection of data items
Order is important

15. Image credit: Frances Dinkelspiel via flickr Creative Commons
By Zzubnik (Own work) [CC-BY-3.0 (http://creativecommons.org/licenses/by/3.0)],
via Wikimedia Commons

16. Stack
Ordered collection of data items
LIFO (Last In First Out)
Only the element at the top may be
accessed at any point in time

17. Stack
Core operations:
push(x)
pop(x)

18. Stack

19. Image credit: Toyhouse.cc Creative Commons
Image credit: gadl via flickr

20. Queue
Ordered collection of data items
FIFO (First In First Out)
Inserts an element at the rear and
ejects an element from the front

21. Queue
Core operations:
enqueue(x) - at rear
dequeue(x) - from front

22. Queue

23. By Choon Boo LIM Creative Commons
By Wilton Scout Group Creative Commons

24. Map
Collection of key-value pairs
Also called a:
Hashtable
Dictionary
Symbol table
Associative array

25. Map

26. By John Gasson Creative Commons
By intotheforest via Flickr Creative Commons
By Da Pino Creative Commons

27. Tree
Collection of nodes (starting at a
root node) where each node
contains a data value and a list of
references to other nodes, with the
constraints that no reference is
duplicated, and none points to the
root

28. Tree

29. By Claudio Rocchini (Own work) [GFDL, CC-BY-
SA-3.0, CC-BY-SA-2.5], via Wikimedia Commons
By Vector Fresh Creative Commons

30. Graph
Finite set of ordered pairs, called
edges or arcs, of certain entities
called nodes or vertices
An edge (x, y) is said to point or
go from x to y

31. Graph

32. Summary
Definition of ADT
Set
List
Stack

33. Summary
Queue
Map
Tree
Graph

34. References
Mike Scott’s set of slides, University of
Texas Austin
Wikipedia
For images:
Wikimedia Commons
Flickr