introduction to computing technologies-ict

7/27/2019 Introduction to Computing Technologies-ICT

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Introduction to Computing Technologies-ICT

Trupti V.G

Name of Book: Fundamentals of computers.

Author: V.Rajaraman

Subject code: 13CT101

Credits: 4


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Chapter 1

Learning Objectives:Idea of an algorithm

Parts of computer

Characteristics of computers

Purpose of computers


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8.3

Informal definition

An informal definition of an algorithm is:

Algorithm: a step-by-step method for solving a

problem or doing a task.

Informal definition of an algorithm used in a computer


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Preparing Maggi

Example

Ingredients:

water 2 cups, maggi noodles 1 pack.

Method: Step 1: Boil 2 cups of water

Step 2: Add maggi noodles to it

Step 3: Add maggi masala to the noodles

Step 4: Cook for 5 minutes till the noodles bake well

Result:

Maggi noodle ready to eat


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Algorithm


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8.6

Example: Finding the largest integer among five integers


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Defining actions

Writing algorithm for the example


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History of algorithm

Algorithm name came from Arab Mathematician Abu

Jafar Mohammed ibn Musa al-khowarizmi

al-khowarizmi was called algorithm.


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Characteristics of algorithm

Finite sequence of instructions. Characteristics:

Begins with inputs, inputs are instructions.

Processing rules specified in the algorithm must beprecise and unambiguous.

Basic instructions that can be understood andcarried out.

Time taken to carry out all the steps in algorithmmust be finite.

It must produce one or more outputs.


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Step 8: average no of vowels=number of vowels/ number of characters

Step 7: Move to next character

Step 6: if the character is any one of the letters A,E,I,O,U,a,e,I,o,u, add

1 to number of vowels

Step 5: add 1 to number of characters

Step 4: read one character from passage

Step 3: repeat steps 4,5,6,7 till end of paragraph

Step 2: let number of vowels=0

Step 1: let number of characters =0

Algorithm to find no of vowels in a paragraph

Step 9: write avg no of vowels, number of characters

Step 10: stop


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Write an algorithm to convert the length in feet to centimeter.

Algorithm

Step 1: Input the length in feet

Step 2: Calculate the length in cm by multiplying LFT

with 30Step 3: Print length in cm


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What is a computer?

An electronic machine that can be programmed to

accept data (input), and process it into useful

information (output).

Computers are devices powered by electricity, whichhas two discrete states: On orOff.


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A simple model of a computer

14

Input unit Memory Output

Processing unit


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Configuration

Input unit: Read the algorithm and data to be processed.

Memory unit:

Stores the algorithm and computes the values.

Processing unit: Interprets the instruction and carries arithmetic operations,

character manipulation operations and logical operations.

Output unit:

Prints or displays result.


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Characteristics of a computer

Processes various instructions. Simple instructions

High speed

Precise

No mistakes


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Problem solving using computers

Steps:

Given problem is analyzed.

Methods broken into sequence of tasks.

Algorithm is expressed in a precise notation

(computer programming language)

Computer program is fed into the computer

Processing is done and results are sent to output unit


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Flowchart

Definition: Pictorial representation of an algorithm.

shows logic of an algorithm

emphasizes individual steps and their

interconnections

Ex: find the total marks and calculate grade.


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19

Rectangles with

rounded ends

Start / stop

Parallelograms

Input / output

Rectangles

to show

Processing

steps

Diamond shape box

For Decision making

Flow of control


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START

Input

M1,M2,M3,M4

GRADE(M1+M2+M3+M4)/4

IS

GRADE


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START

Input

Length in feet

Length in cm Lft x 30

Print

Length in cm

STOP

Draw a flowchart to convert the length in feet to centimeter.


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Programming Language: expressing flowchart in amore precise and concise notation.

Examples: Java programming language, c, FORTRANClass a

{public static void main(String[] args)// an example of java

program

{ int m1=10, m2=20, m3=40, m4=35;

int avg;

avg=(m1+m2+m3+m4)/4;

System.out.println(avg);

} }

A Program


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Stored program concept

Model of a computer: Proposed by John Von

Neumann in 1945.

Concept: Storing a program and processing the data

in the same memory Use: Repetitive execution of series of instructions.

Storing a program in memory makes the operations

automatic without human intervention.


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Write an algorithm and draw a flowchart that will read the two

sides of a rectangle and calculate its area

Algorithm

Step 1: Input W,L

Step 2: A L x W

Step 3: Print A

Pseudocode

Input the width (W) and Length (L) of a

rectangle

Calculate the area (A) by multiplying Lwith W

Print A

START

Input

W, L

A L x W

Print

A

STOP


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Write an algorithm and draw a flowchart that will calculate the roots

of a quadratic equation ax2+bx+c=0

Hint: d = sqrt ( ), and the roots are:x

1 = (

b + d)/2a andx2 = (b d)/2a

24b ac

Algorithm:

Step 1: Input a, b, cStep 2: d sqrt ( )

Step 3: x1 (b + d) / (2 x a)

Step 4: x2 (b d) / (2 x a)

Step 5: Printx1,x2

START

Input

a, b, c

d sqrt(b x b 4 x a x c)

Print

x1 ,x2

STOP

x1(b + d) / (2 x a)

X2 (b d) / (2 x a)

4b b a c


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General Concept

How does one figure out the percentage of several

marks?

Add them all up

Divide by the maximum possible mark (50+20+70)

Multiply by 100

Given 3 assignment marks (out of 50, 20, 70), find the average(calculated as a mark out of 100)


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Given 3 assignment marks (out of 50, 20, 70), find theaverage, calculated as a mark out of 100

Algorithm:Set MaxMark = 140 (Constant)

Step 1: Get A1

Step 2: Get A2

Step 3: Get A3

Step 4 Let Total = A1 + A2 + A3

Step 5: Let Mark = Total/MaxMark * 100

Step 6: display result


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Given a two digit number, find the

sum of its digits

General Concept

How can we break apart a number?

41 = 4 Tens and 1 Ones

so for the number 41, we want 4 + 1 = 5

Use integer division

DIV returns the integer part of a

division

MOD returns the remainder of adivision

41 / 10 = 4

41 MOD 10 = 1


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Given a two digit number, find the sum of its digits

ALGORITHM:

Step 1: Get N

Step 2: Let Tens = N div 10

Step 3: Let Ones = N mod 10

Step 4: Let Sum = Tens + Ones

Step 5: Display Sum


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Exercise problems

Write an algorithm and flowchart to add two numbers

and check if the resulting number is even or odd.

Write an algorithm to find the direction or path from

PESIT to chinnaswamy stadium.

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