COMSCI 1201 LEC (Data Structures & Algorithms)

refers to a collection of individual values that can take many forms, such as text, images, audio, or video, usually represented with the help of characters such as alphabets, digits, or special characters.

Data

examples of data are:

names, ages, prices, costs, numbers of items sold, employee names, etc.

Data themselves are fairly useless, but when these data are processed or organized, they become useful and is now called__

information.

data needs to be __ to provide information.

organized

__ is a storage that is used to store and organize data. It is a way of arranging data on a computer so that it can be accessed and updated efficiently.

data structure

it easy for users to access and work with the data they need in appropriate ways.

data structure

Data Structure It is not only used for organizing the data but also for ___using various algorithms.

processing, retrieving, and storing data

Data structure is classified into two types

primitive and non-primitive.

Also known as basic data structure, it contains fundamental data types that can only hold single data type values.

Primitive data structure

Examples of primitive data

integer, character, boolean, float, double, long, etc.

a data structure that focuses on forming a set or collection of data elements that is either homogeneous or heterogeneous

Non-primitive data structure

What is Homogenous and its example?

(same data type. ex. integer array num)

What is Heterogeneous

and its example?

(different data types. ex. structure Student that contains char array name, integer age, etc.)

Non-primitive data structure also known as ___, as they are derived on primitive ones.

derived data structure

A ___ can be stored using the non- primitive data structures.

large number of values

The data stored can also be manipulated using various operations like

• insertion,

• deletion,

• searching,

• sorting,

Non-primitive data structures are divided into two categories:

linear and non-linear data structures

a type of data structure in which data elements are arranged sequentially or linearly.

Linear data structure

Since elements are arranged in a sequential or particular order, linear data structure is __

easier to access.

Examples of linear data structures are__

array, stack, queue, and linked list.

When the elements of a data structure doesn't stay sequentially or linearly, the data structure is called to be __

Non-linear data structure

Since the data structure is non-linear, it does not involve a__. Therefore, they can’t_ all of its elements in a single run.

• single level

• traverse

examples of non-linear data structures.

Trees and graphs

What are the Data Structure Operations ( enumerate)

• Navigating

• Searching

• Insertion

• Deletion

• Sorting

• Merging

Accessing each data element exactly once so that certain items in the data may be processed

Navigating

Finding the location of the data element or key in the structure.

Searching

Adding a new data element to the structure

Insertion

Removing a data element from the structure

Deletion

Arrange the data elements in a logical order (ascending/descending)

Sorting

Combining data elements from two or more data structures into one

Merging

defined as a step-by-step procedure or method with a finite set of instructions to accomplish a particular task.

algorithm

Basically, it is not the complete code, rather it is the__ that can be implemented to solve a particular problem.

logic

While defining an algorithm, steps are written in human understandable language and independent of any programming language, which are usually represented by using___

flowcharts or pseudocode.

Algorithm =

Algorithm = Input + Process + Output

What are the Characteristics of an Algorithm ( enumerate)

• Unambiguous

• Inputs

• Outputs

• Correctness

• Finiteness

• Effectiveness

• Language Independent

Instructions in an algorithm should be clear, simple, and straightforward.

Unambiguous

An algorithm should have some input values.

Inputs

At the end of an algorithm, you must have one or more outcomes.

Outputs

An algorithm is designed correctly if it receives valid input, terminates, and always returns the correct output.

Correctness

The algorithm should contain a limited and countable number of instructions and should terminate after a finite time.

Finiteness

Each step of the algorithm should be effective and efficient enough to produce results.

Effectiveness

The effectiveness of an algorithm can be evaluated with the help of two important parameters:

1. Time Complexity

2. Space Complexity

This refers to the amount of time taken by the computer to run the algorithm.

Time Complexity

the total space taken or amount of computational memory needed by the algorithm to solve a problem.

Space Complexity

Instructions in an algorithm can be implemented in any language and produce the same results.

Language Independent

Data Flow of an Algorithm (enumerate)

• Problem

• Algorithm

• Input

• Processing Unit

• Output

usually gives the programmer an idea of the issue at hand, the available resources and the motivation to come with a plan to solve it.

Problem

programmer designs the step by step procedure to solve the problem efficiently.

Algorithm

algorithm is designed and the relevant inputs are supplied.

Input

receives these inputs and processes them as per the designed algorithm.

Processing Unit

receive the favorable output of our problem statement

Output

What Makes a Good Algorithm?

• It must be correct • It must be finite (in terms of time and size) • It must terminate • It must be unambiguous • It must be space and time efficient