Introduction to C

1. Introduction to Computer
Programming
Faculty In charge
Achsah Susan Mathew, MCA, MBA, KSET, (PhD)
Assistant Professor, Kristu Jayanti College
achsah@kristujayanti.com

2. Let Us Start
What is Computer ?

3. • It is Dumb Machine

5. Understands only 0/1(Binary or Bit)
• How do we interact with the computer and
make it to work
using Programming languages such as
C, C++, Java, C#, PHP, Python, Erlang etc.
(Translators)
Complier /Interpreter/
Assembler

7. Machine language

8. Mnemonic Code(English like)

9. High Level language
• C, C++, Java, C# etc. (has a syntax to follow)

10. Translators
1.Compiler
2.Interpreter
3.Assembler
Convert the programs Machine code

11. • Compiler converts the complete program to
machine code

12. • Interpreter
High level language/Source code
(C,C++,Java)
Conversion happens line by line
Machine Lang
(0/1)
Source code 011011(ML)
Object Code
Interpreter

13. • Assembler(Assembly language to 0/1 )

14. Linker

16. Loader(Load .exe file to RAM for the output)

18. • Computer is an electronic device that stores
the data that it receives processes the data
and gives the output

19. What is a Program
Set of instructions
• Written in Computer languages(c, c++ ,Java
etc.
• To perform some task

20. Instruction to Add Two numbers
• Get first no
• Get Second no
• Use symbol + to add 1st no and 2nd no
• Show the result
Therefore, Instructions can be one line of code or
many lines of code
------- Program (many lines of code)

21. What is Software
• Group of programs is called Software
Programs Programs Programs
Software

22. What is Hardware
• Electronic devices that can be touch and felt

23. Classification of Software

24. System Software
• System software is a set of programs that
manages the system
• System Software that helps to use hardware
efficiently

25. • It acts as an interface between hardware and the
end users
• System Software are the basic necessity for the
hardware to functioning properly
Hardware System Software End user

26. Application Software
• Is a Set of programs designed to perform
specific task
• Collection of programs often called software
package which work together to perform
some task

29. Steps in Problem Solving

30. Steps

31. 1.Problem Definition
• To Solve a problem –Identify
Define the Problem
It should be clear, accurate and precise
Problem: Addition of two numbers
Find the value and nature of roots of
quadratic eqn

32. 2.Problem Analysis
• Proper Analysis of the problem is required
• Which helps in designing and coding(next
steps)
• Proper Analysis of
Input Specification: What is the input to be
given, how many inputs to be given
Output Specification: What is the output that is
expected

33. • Problem Definition: Find the sum of 3
numbers
• Problem Analysis: I/p :3 numbers
o/p: Sum of 3 numbers

34. 3.Desigining a program
• Designing using Programming tools such as
Algorithms: Step by step procedure to
solve a problem
Flowchart: Graphical representation
of the algorithm

35. Algorithms
Step by step procedure to solve a problem
Derived from Arab Mathematician
Al-khowarizmi

36. Write an Algorithm for making a telephone call
• Step1:Start
• Step2:Pick up the receiver
• Step3:Listen to the dial tone
• Step4:Dial the phone number
• Step5:When Someone answers talk
• Step6:Sat “Bye”
• Step7:Hang up the receiver
• Step8:Stop

37. Write an Algorithm for Addition of two
number
• Step1:Start
• Step2:Read two numbers a, b /Get two
numbers a, b
• Step3: Perform addition and store in c
c=a + b
• Step4:Print the result c
• Step5:Stop

38. Write an Algorithm for Subtraction of two
number
• Step1:Start
• Step2:Read two numbers a, b /Get two
numbers a, b
• Step3: Perform addition and store in c
c=a - b
• Step4:Print the result c
• Step5:Stop

39. Average of three numbers
• Step1:Start
• Step2:Read three numbers a,b,c
• Step3:Average=(a+b+c)/3
• Step4:Print Average
• Step5:Stop

40. Find out discriminant of quadratic eqn
Formula
discriminant :𝑏2 − 4𝑎𝑐
Step1: Start
Step2:Read the values for a, b,c
Step3:discriminant= b*b-4*a*c
Step4:Print discriminant
Step5:Stop

41. Find Simple Interest
• Formula:
Simple Interest = (PTR)/100
Write the Algorithm
Step1:Start
Step2:Read PTR
Step3:SI=(P*T*R)/100
Step4:Print SI
Step5:Stop

42. Write an algorithm to find greatest of
two number
• Step1:Start
• Step2:Read a, b
• Step3:If (a>b) then
print “a is greater”
else
print “b is greater”
• Step4:Stop

43. • Advantages:
1.Very easy to understand
2.Easy to first develop algorithm flowchart
3.Machine independent(do not depend on any
machine)
4.Programming language independent
5.It explains in short
6.Easy to fix errors
7.Does not require computer knowledge

44. • Disadvantage:
1.Time Consuming
2.Trial and error procedure
3.Big tasks are difficult to put in Algorithm

45. Flow Chart
• Graphical representation of the algorithm or
• Pictorial representation of an algorithm is
called as Flowchart
Two Type:
System Flowcharts :Flow of the data within the
system
Program Flowchart :Flow of the Program

46. Flow Chart Symbols
• Start and Stop(oval)
• Input/Output(parallelogram)

47. • Process or Arithmetical calculations(rectangle)
All Calculations such as Addition, sub, mul, div,
logical comparing is done with the processing
symbol
• Decision Making(Diamond):yes or no
decisions(t/f)
Yes
No

48. • Connector: Connect two programs
• Route Marker: Indicate the direction
• Predefined Process
Process that is used several times, used as a
reference

49. • Looping: group of instruction to be executed
repeatedly eg: for loops, while

50. Characteristics of flowchart
• 1.Useful tool in program development
• 2.Identifying the steps that are must for the
solution
• 3.Identifying the decision point
• 4.Knowing the expected results

51. Advantage and Disadvantage of
Flowcharts

52. Eg: Addition of 2 number

53. Eg: Average of 3 numbers

55. Achsah Susan Mathew, MCA, MBA, KSET, (PhD)
Assistant Professor, Kristu Jayanti College
Staff Room: (2nd Floor Main Block (VIII) Cabin 5)
achsah@kristujayanti.com