all about algorithm and flowchart

1. CLASS : 7
Subject : Computer
Topic: programming technique
Good morning
students

2. introduction
 Computers can not perform any task on their own.
 They need instruction to tell them what to do , how to do
and when to do.
 A set of instruction that direct the computer to do a
specific task is called a program.
 A task is actually a problem that is tracked by a
programmer.
 Programming problem need to be divided in to smaller
step .

3. Continue…….
 So that each step can be formulated in the form of an
instruction written in a programming languages.
 The activity is termed as a computer programming.
 Computer programming is a sequence of steps requires
for a solving a problem with the help of computer
programming are algorithm , flowchart and pseudo
code(source code).

4. An algorithm is a step by step
procedures to solve a particular
problem.
It has a finite number of steps.
To write algorithm , we use simple
English language.

5. General rules for writing an Algorithms:
 An algorithm should have finite number
of steps.
 Algorithm should not dependent on a
particular computer language.
 The step should be executable by
computer.
 Algorithm is independent of
programming language.
 An algorithm must produce an output.

7. Characteristics of Algorithms:
 Precision – the steps are precisely
stated(defined).
 Uniqueness – results of each step are
uniquely defined and only depend on the
input and the result of the preceding steps.
 Finiteness – the algorithm stops after a finite
number of instructions are executed.
 Input – the algorithm receives input.
 Output – the algorithm produces output.
 Generality – the algorithm applies to a set of

9. Advantages of algorithm
 It is a step-wise representation of a solution
to a given problem, which makes it easy to
understand
 It is not dependent on any programming
language, so it is easy to understand for
anyone even without programming
knowledge.
 Every step in an algorithm has its own
logical sequence so it is easy to debug.
 By using algorithm, the problem is broken
down into smaller pieces or steps hence, it

10. Disadvantages of algorithm
 Algorithms is Time consuming.
 Difficult to show Branching and
Looping in Algorithms.
 Big tasks are difficult to put in
Algorithms
 Writing algorithm takes a long time.
 An Algorithm is not a computer
program, it is rather a concept of how
a program should be.

11. solved examples
1. Write an algorithm to give instruction for making maggi
noodles as a food.
 Step 1: Start
 Step 2: Take pan with water
 Step 3: Put pan on the burner
 Step 4: Switch on the gas/burner
 Step 5: Put magi and masala
 Step 6: Give two minutes to boil
 Step 7: Take off the pan
 Step 8: Take out the magi with the help of fork/spoon
 Step 9: Put the Maggi on the plate and serve it
 Step 10: Stop

12. solved examples
1. Write an algorithm to make cup of tea.
 Step 1:Put the teabag in a cup.
 Step 2:Fill the kettle with water.
 Step 3:Boil the water in the kettle.
 Step 4:Pour some of the boiled water into
the cup.
 Step 5:Add milk to the cup.
 Step 6:Add sugar to the cup.
 Step 7:Stir the tea.
 Step 8:Drink the tea.

14. solved examples
1. Write an algorithm to find simple interest.
 Step 1:Start
 Step 2:Read Principal Amount, Rate and
Time
 Step 3:Calculate Interest using formula SI=
((principal*rate*time)/100)
 Step 4:Print Simple Interest
 Step 5:Stop

15. solved examples
1. Write an algorithm to find area of circle.
 Step1: Start
 Step2: Input the the value of radius R
 Step3: Let PI=3.14
 Step4: Calculate area=PI*R*R
 Step5: Print area
 Step6: End

16. solved examples
1. Write an algorithm to find greatest number
among two number.
 Step1: Start
 Step2: Input number1 and number2
 Step3: is a>b ?
-if yes print “a is greatest number”
-if no print “b is greatest number”
 Step4: End

17. solved examples
1. Write an algorithm to find area of rectangle.
 Step1: Start
 Step2: take length and breadth and store in
it L and B.
 Step3: multiply L and B and store in it area.
 Step4: print area
 Step5: End

19. Advantages of flowchart
 The Flowchart is an excellent way of communicating the
logic of a program.
 It is easy and efficient to analyze problem using flowchart.
 During program development cycle, the flowchart plays the
role of a guide or a blueprint. Which makes program
development process easier.
 After successful development of a program, it needs
continuous timely maintenance during the course of its
operation. The flowchart makes program or system
maintenance easier.
 It helps the programmer to write the program code.
 It is easy to convert the flowchart into any programming
language code as it does not use any specific

20. Disadvantages of flowchart
 The flowchart can be complex when the logic of a program
is quite complicated.
 Drawing flowchart is a time-consuming task.
 Difficult to alter the flowchart. Sometimes, the designer
needs to redraw the complete flowchart to change the logic
of the flowchart or to alter the flowchart.
 Since it uses special sets of symbols for every action, it is
quite a tedious task to develop a flowchart as it requires
special tools to draw the necessary symbols.
 In the case of a complex flowchart, other programmers
might have a difficult time understanding the logic and
process of the flowchart.
 It is just a visualization of a program, it cannot function like
an actual program

24. Flowchart for area of rectangle