The document outlines the course structure for IT 4043: Data Structures and Algorithms, including lecture and practical hours, assessments, and a syllabus covering topics like abstract data types, list operations, stacks, and algorithms. It also discusses data structures such as arrays, linked lists, and their applications in real-world data storage. Additionally, examples of methods and implementations related to linear lists and abstract data types are provided.

1. IT 4043
Data Structures and Algorithms
Budditha Hettige
Department of Computer Science
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2. IT4043: Data Structures and Algorithms
• Lectures
– 30 Hours
• Practical /Tutorials
– 30 hours
• Assignment (30%)
– Practical Test (10 marks)
– Quizzes 4 (Get maximum 2 ) (10 x2 = 20 marks )
– Total 30%
• Final Examination (70 %)
– 4 Questions (3 hours) (70%)
• Reference:
– https://budditha.wordpress.com/
7/11/2015 Budditha Hettige (budditha@yahoo.com) 2

3. Syllabus
• Introduction to DSA
• Abstract Data Types
• List Operation Using Arrays
• Stacks
• Queues
• Recursion
• Link List
• Sorting
• Searching
• Algorithms Analysis
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4. Introduction

5. Data Structure
• Data + Structure
• A data structure is an arrangement of data in a
computer’s memory (or sometimes on a disk).
• Example:
– arrays
– linked lists
– Stacks
– Queues
– binary trees
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6. • Algorithms
• Algorithms manipulate the data in these
structures in various ways, such as searching for
a particular data item and sorting the data.
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7. Example:
Algorithms for searching/Sorting
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8. Example
• Write a Java program enter 10 integer number in to an
array
• Write 2 method findMin() and findMax() that returns
smallest and largest value of the above data set.
• Write a method name findItem(int index) that return a
value of the given array index
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7 3 9 2 4 7 5 3 6 8

9. Data Structures and Algorithms for..
• Real-world data storage
– A personnel record describes an actual human being
– An inventory record describes an existing car part or
grocery item
– A financial transaction record describes, an actual
check written to pay the electric bill.
• Programmer’s tools
• Modeling
Data Structures and Algorithms 9

10. Advantages & Disadvantages
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11. Abstract Data Types (ADT)

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Abstract Data Type (ADT)
• ADT is a collection of data and a set of
operations that can be performed on the data.
• It enables us to think abstractly about the data …
• We can separate concepts from
implementation.
• Typically, we choose a data structure and
algorithms that provide an implementation of an
ADT.

13. ADT
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Data Methods
• Simple Example
– Points
– Line
– Shape
– Length
– Matrix
– Vector
• Advanced Example
– List
– Stack
– Queue
– Link List
– Trees

14. Point Example
• Methods
– Point()
– Point(int x, int y)
– Point(Point p)
– getX()
– getY()
– setX()
– setY()
– getLength()
– addX(int x)
– addY(int y)
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15. Line Example
• Attribute
– 2 Line
• Methods
– Line()
– Line(P1, P2)
– getLength()
– getArea()
– getX()
– getY()
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16. Shape Example
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17. Example –Length (feet-inch)
• Length()
• Length(Feet, Inch)
• Add(L1, L2)
• Subtract(L1, L2)
• Print ()
• getFromMeter(float Len )
• getMeter()
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18. List

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Linear List
• Definitions
– Linear list is a data object whose instances are of the form
(e1,e2,…,en)
– ei is an element of the list.
– e1 is the first element, and en is the last element.
– n is the length of the list.
– When n = 0, it is called an empty list.
– e1 comes before e2, e2 comes before e3, and so on.
• Examples
– student names order by their alphabets
– a list of exam scores sorted by descending order

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Implementations of Linear List
• Array-based (Formula-based)
– Uses a mathematical formula to determine where (i.e., the memory address)
to store each element of a list
• Linked list (Pointer-based)
– The elements of a list may be stored in any arbitrary set of locations
– Each element has an explicit pointer (or link) to the next element
• Indirect addressing
– The elements of a list may be stored in any arbitrary set of locations
– Maintain a table such that the ith table entry tells us where the ith element
is stored
• Simulated pointer
– Similar to linked representation but integers replace the C++ pointers

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ADT for LinearArrayList
class LinearArrayList {
Methods
Create(): create an empty linear list
Create(s): create a list with size s
IsEmpty(): return true if empty, false otherwise
ISFull(): return true if List is full
Length(): return the list size
Find(k): return the kth element of the list
Search(x): return the position of x in the list
Delete(k): delete the kth element and return it
Insert(k,x): insert x just after the kth element
Print(out): put the list into the output stream out
Add(x): Add new item to the list
Clear(): clear all items
Remove(): Remove top item of the list
}

22. Array List
• createList()
• insertFirst()
• insertLast()
• insertMiddle()
• isFull()
• findItems()
• print()
• clear()
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23. Array List
• Remove Item from list
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24. Example (Java Code)
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