Computer programming lecture – 05 to 11

Lecture – 05 to 11Computer Programming

14 Computer Systems Engineering – Second Semester

By: Mr. Ali Asghar Manjotho, Lecturer, CSE-MUET

Contents

• Problem analysis tools

• IPO (Input, Process, Output) chart (LL 04)

• Algorithm (LL 04)

• Flow Chart (LL 04)

• Problem Examples (LL 04)

LL 04 = Learning Level 04 – Analysis

Ali Asghar Manjotho, Lecturer CSE-MUET 2

Problem analysis tools



• Problem analysis tools help you analyze the problem to have a clear picture of the problem.

• They help you identify the problems and their causes at the beginning.

• They help you better understand the problem by conducting its postmortem.



• The problem analysis tools that we will be using to solve problem are:


IPO Chart

• IPO stands for Input Process Output.

• It performs the analysis by identifying the input, process and output of a given problem.


IPO Chart

• It can be represented by the following chart:


Input Processing Output

Processing Items:

Algorithm:

IPO Chart

• The input section specifies all the inputs to the problem.

• The input may be given by the user from input devices like, keyboard, mouse, scanner etc.

• The input may also come as the contents of a file.

• The input may come from the network or Internet.


IPO Chart

• The output section specifies all the outcomes of the problem.

• The output may be in the form of the presenting the results on the monitor screen, printer or any other output device.

• The output may also be stored in a file.

• The output may be redirected to network or Internet.


IPO Chart

• The processing section specifies two things: processing items and algorithm.

• The processing items involve any formula or equation to be used while processing.

• The algorithm is the step by step processing procedure to solve that task.


Algorithm

• Algorithm is the representation of a solution to a problem.

• It is step by step procedure to solve a given problem.

• An algorithm contains finite number of instructions in order to solve a problem.


Algorithm

• For example, calculating the average of three numbers.

Step 01: Start

Step 02: Input number1, number2 and number3 from the user

Step 03: Calculate average as: average = (number1 + number2 + number3)/3

Step 04: Print average

Step 05: End


Flow Chart

• Flow chart is the pictorial representation of a process or an algorithm.

• It uses symbols (boxes of different shapes) to represent each step of an algorithm.

• All the symbols are then connected with arrows to show the flow of the process.


Flow Chart


Symbol Name Meaning

Terminal(Oval)

Indicates the beginning and end points of an algorithm.

Process(Rectangle)

Shows an instruction other than input, output or selection.

Flow Chart


Symbol Name Meaning

Input-Output(Parallelogram)

Shows an input or output instruction.

Decision(Diamond)

Shows any point in the process where decision is to be made.

Flow Chart


Symbol Name Meaning

On-PageConnector

Continues and connects the flowchart on the same page.

Off-PageConnector

Continues and connects the flowchart on another page.

Flow Chart


Symbol Name Meaning

Sub-ProcessDenotes movement to another process and hence a new flowchart

ArrowsConnects symbols and shows flow of the process or algorithm.

Problem ExamplesIPO Charts, Algorithms and Flow Charts


Problem 01: Area of rectangle

Problem Statement: Write a program that accepts the width andthe height of a rectangle from the user and prints the area of therectangle.


Problem 01 - IPO Chart and Algorithm



• Width of rectangle• Height of rectangle

Processing Items:area = width * height

Algorithm:Step 01: StartStep 02: Input width and height from the userStep 03: Calculate area as: area = width * heightStep 04: Print areaStep 05: End

• Area of rectangle

Problem 01 – Flow Chart


Problem 02 : Average of three numbers

Problem Statement: Write a program that accepts three numbersfrom the user and displays the average of the numbers.





• First number• Second number• Third number

Processing Items:average = (number1 + number2 + number3)/3

Algorithm:Step 01: StartStep 02: Input number1, number2 and number3

from the userStep 03: Calculate average as: average =

(number1 + number2 + number3)/3Step 04: Print averageStep 05: End

• Average of numbers



Problem 03 : Temperature scale conversion

Problem Statement: Write a program that receives thetemperature in Celsius from the user and displays the temperaturein Fahrenheit and Kelvin.





• Temperature inCelsius

Processing Items:F = C * 1.8 + 32K = C + 273.15

Algorithm:Step 01: StartStep 02: Input Celsius c from the userStep 03: Calculate Fahrenheit temperature as:

f = (c * 1.8) + 32Step 04: Calculate Kevin temperature as:

k = c + 273.15Step 05: Print f and kStep 06: End

• Temperature in Fahrenheit

• Temperature in Kelvin



Problem 04 : Area and circumference of a circle

Problem Statement: Write a program that receives the radius ofthe circle from the user and displays the area and circumference ofthe circle.





• Radius of circle Processing Items:area = π * radius^2circumference = 2 * π * radius

Algorithm:Step 01: StartStep 02: Input radius from the userStep 03: set PI = 3.1415Step 04: Calculate area as: area = PI * radius^2Step 05: Calculate circumference as:

circumference = 2 * PI * radiusStep 06: Print area and circumferenceStep 07: End

• Area of circle• Circumference of

circle



Problem 05 : Buntty, Bubbly and Building

Problem Statement: There are two friends Buntty and Bubbly.Buntty is standing at the top of a vertical building and Bubbly isstanding on the ground away from the building. Write a programthat displays the distance of Bubbly from the building after askingthe user about the length of the building and the distance betweenBuntty and Bubbly.





• Distance between Buntty and Bubbly

• Height of the Building

Processing Items:Hyp2 = Base2 + Perp2

Hyp = Distance b/w Buntty and BubblyBase = Distance b/w Bubbly and buildingPerp = Height of building

Base = 𝐻𝑦𝑝2 + 𝑃𝑒𝑟𝑝2

Algorithm:Step 01: StartStep 02: Input Dis_Bun_Bub, Height_Bui from the userStep 03: Calculate Distance b/w Bubbly and building as:

Dis_Bub_Bui = 𝐷𝑖𝑠_𝐵𝑢𝑛_𝐵𝑢𝑏2 + 𝐻𝑒𝑖𝑔ℎ𝑡_𝐵𝑢𝑖2

• Distance of Bubbly fromthe building




Step 04: Print Dis_Bub_BuiStep 05: End



Problem 06 : Notes and Coins

Problem Statement: A person enters the bank and stands in thequeue to get his salary. When his turn comes, he requests thecashier that I need my salary with minimum notes and coins. Writea program for the cashier that first asks the cashier to enter thesalary amount and then displays the number of notes and coins of(Rs. 5000, Rs. 1000, Rs. 100, Rs. 50, Rs. 20, Rs. 10, Rs. 5, Rs. 2 andRe. 1).





• Salary amount

Processing Items:No of notes = 𝑠𝑎𝑙𝑎𝑟𝑦/𝑛𝑜𝑡𝑒_𝑎𝑚𝑜𝑢𝑛𝑡No of coins = 𝑠𝑎𝑙𝑎𝑟𝑦/𝑐𝑜𝑖𝑛_𝑎𝑚𝑜𝑢𝑛𝑡

Algorithm:Step 01: StartStep 02: Input salary from the userStep 03: Calculate notes of 5000 as:

notes_5000 = 𝑠𝑎𝑙𝑎𝑟𝑦/5000

Step 04: Recalculate salary as: salary = salary – (notes_5000 * 5000)

Step 05: Calculate notes of 5000 as:notes_1000 = 𝑠𝑎𝑙𝑎𝑟𝑦/1000


• Number of notes of 5000• Number of notes of 1000• Number of notes of 500• Number of notes of 100• Number of notes of 50• Number of notes of 20• Number of notes of 10• Number of coins of 5• Number of coins of 2• Number of coins of 1

















Step 17: Calculate coins of 5 as:coins_5 = 𝑠𝑎𝑙𝑎𝑟𝑦/5

Step 18: Recalculate salary as: salary = salary – (coins_5 * 5)

Step 19: Calculate coins of 2 as:coins_2 = 𝑠𝑎𝑙𝑎𝑟𝑦/2

Step 20: Recalculate salary as: salary = salary – (coins_2 * 2)




Step 21: Calculate coins of 1 as:coins_1 = salary

Step 22: Print notes_5000, notes_1000, notes_500, notes_100, notes_50, notes_20, notes_10, coins_5, coins_2, coins_1

Step 23: End





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Problem 07 : Even or odd number

Problem Statement: Write a program that receives an integernumber from the user and displays whether it is an even number oran odd number.





• Integer number Processing Items:If (number MOD 2) = 0 then it is evenIf (number MOD 2) ≠ 0 then it is odd

Algorithm:Step 01: StartStep 02: Input number from the userStep 03: if (number MOD 2) == 0 then GOTO Step 04

else GOTO Step 05Step 04: Print “Number is even” GOTO Step 06Step 05: Print “Number is odd”Step 06: End

• Number is odd or even



Problem 08 : Positive numbers

Problem Statement: Write a program that receives an integernumber from the user. If the number is positive then display thatnumber.





• Integer number Processing Items:If (number > 0) then it is positive

Algorithm:Step 01: StartStep 02: Input number from the userStep 03: if (number > 0) then GOTO Step 04 else

GOTO Step 05Step 04: Print number Step 05: End

• Number if it is positive



Problem 09 : Largest number

Problem Statement: Write a program that receives three uniqueinteger numbers from the user and displays the largest number.





• First number• Second number• Third number

Processing Items:If (num1> num2 and num1 > num3) then num1 is largestIf (num2> num1 and num2 > num3) then num2 is largestIf (num3> num1 and num3 > num2) then num3 is largest

Algorithm:Step 01: StartStep 02: Input num1, num2 and num3 from the userStep 03: if (num1> num2 and num1 > num3) then GOTO

Step 05Step 04: if (num2> num1 and num2 > num3) then GOTO

Step 06 else GOTO Step 07

• Largest number




Step 05: Print num1 GOTO Step 08Step 06: Print num2 GOTO Step 08Step 07: Print num3Step 08: End



Problem 10 : Marks sheet

Problem Statement: Write a program that receives the marks offive different subjects from the user and displays the percentageand grade obtained.





• Marks of firstsubject

• Marks of second subject

• Marks of third subject

• Marks of fourth subject

• Marks of fifth subject

Processing Items:Percentage = (Obtained marks/Total marks)*100If(Percentage >= 85) grade = A+ If(Percentage >= 80 and Percentage <= 84) grade = AIf(Percentage >= 75 and Percentage <= 79) grade = B+If(Percentage >= 70 and Percentage <= 74) grade = BIf(Percentage >= 65 and Percentage <= 69) grade = C+If(Percentage >= 60 and Percentage <= 64) grade = CIf(Percentage >= 55 and Percentage <= 59) grade = D+If(Percentage >= 50 and Percentage <= 54) grade = DIf(Percentage <= 49) grade = F

• Percentageof marks

• Grade obtained




Algorithm:Step 01: StartStep 02: Input marks of subjects sub1, sub2, sub3, sub4 and sub5

from the userStep 03: Calculate percentage as :

per = ((sub1 + sub2 + sub3 + sub4 + sub5)/500)*100Step 04: If (per>=85) then grade=“A+” GOTO Step 10Step 05: If (per>=80 and per<=84) then grade=“A” GOTO Step 13Step 06: If (per>=75 and per<=79) then grade=“B+” GOTO Step 13Step 07: If (per>=70 and per<=74) then grade=“B” GOTO Step 13Step 08: If (per>=65 and per<=69) then grade=“C+” GOTO Step 13Step 09: If (per>=60 and per<=64) then grade=“C” GOTO Step 13Step 10: If (per>=55 and per<=59) then grade=“D+” GOTO Step 13Step 11: If (per>=50 and per<=54) then grade=“D” GOTO Step 13




Step 12: If (per<=49) then grade=“F” Step 13: Print per, gradeStep 14: End





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Problem 11 : First 10 integer numbers

Problem Statement: Write a program that generates and displaysfirst 10 integer numbers.





Processing Items:1, 2, 3, . . . , 10

Algorithm:Step 01: StartStep 02: Set i = 1Step 03: Repeat Step 04 to Step 05 while i <=10Step 04: Print iStep 05: Set i = i + 1Step 06: End

• First 10 integer numbers



Problem 12 : Sum of first N integer numbers

Problem Statement: Write a program that displays sum of first Ninteger numbers. Where as the number N is provided by the user.





• Number N Processing Items:Sum = 1 + 2 + 3 + , . . . , + N

Algorithm:Step 01: StartStep 02: Input N from the userStep 03: Set i = 1, sum = 0Step 04: Repeat Step 05 to Step 06 while i <=NStep 05: Set sum = sum + iStep 06: Set i = i + 1Step 07: Print sumStep 08: End

• Sum of first N integers



Problem 13 : First N even numbers

Problem Statement: Write a program that generates and displaysfirst N even numbers. Where as the number N is provided by theuser.





• Number N Processing Items:2N

Algorithm:Step 01: StartStep 02: Input N from the userStep 03: Set i = 1Step 04: Repeat Step 05 to Step 06 while i <=NStep 05: Print 2*iStep 06: Set i = i + 1Step 07: End

• First N even number



Problem 14 : First N multiples of 5

Problem Statement: Write a program that generates and displaysfirst N multiples of 5. Where as the number N is provided by theuser.





• Number N Processing Items:5, 10, 15, 20, 25, . . . , N*5

Algorithm:Step 01: StartStep 02: Input N from the userStep 03: Set i = 1Step 04: Repeat Step 05 to Step 06 while i <=NStep 05: Print i * 5Step 06: Set i = i + 1Step 07: End

• First N multiples of 5




• Number N Processing Items:5, 10, 15, 20, 25, . . . , N*5

Algorithm:Step 01: StartStep 02: Input N from the userStep 03: Set i = 5Step 04: Repeat Step 05 to Step 06 while i <=N*5Step 05: Print iStep 06: Set i = i + 5Step 07: End

• First N multiples of 5





Problem 15 : Factorial of a number

Problem Statement: Write a program that receives a positiveinteger number from the user and displays its factorial.





• Number N Processing Items:N! = N * (N-1) * (N-2) * , . . . , * 1

Algorithm:Step 01: StartStep 02: Input N from the userStep 03: Set i = N , factorial = 1Step 04: Repeat Step 05 to Step 06 while i >1Step 05: Set factorial = factorial * iStep 06: Set i = i - 1Step 07: Print factorialStep 08: End

• Factorial of N



Problem 16 : Prime or composite number

Problem Statement: Write a program that receives a positiveinteger number from the user and displays whether it is a prime orcomposite number.





• Number N Processing Items:Prime number = (N MOD n) ≠ 0, where n= 2 to (N-1)Composite number = Otherwise

Algorithm:Step 01: StartStep 02: Input N from the userStep 03: Set i = 2 , isPrime = trueStep 04: Repeat Step 05 to Step 06 while i < NStep 05: if (N MOD i) = 0 then isPrime = false GOTO Step 07Step 06: Set i = i + 1Step 07: if isPrime = true GOTO Step 08 else GOTO Step 09

• N is prime or composite




Step 08: Print “Number is prime” GOTO Step 10Step 09: Print “Number is composite”Step 10: End



Education

Computer programming lecture – 05 to 11