An algorithm is a set of steps to solve a problem. It has four characteristics: finiteness, definiteness, effectiveness, and inputs/outputs. To develop an algorithm, one identifies the inputs, outputs, logic, breaks the logic into simple steps, and writes the steps in order. A flowchart is a pictorial representation of an algorithm that uses standard symbols like rectangles, diamonds, and arrows. It shows the flow of instructions and is easier to understand than an algorithm. Examples are provided to write algorithms and flowcharts to convert feet to centimeters and calculate the area of a rectangle.

1. Flowcharts and algorithms
Prepared by:
Ravi Bharadva 130110120007
Hemdeep Bhavsar 130110120008
Nayan Chauhan 130110120009
Chintan Kathrecha 130110120010
Chitt Kakadia 130110120011
Yashraj Chudasama 130110120012
Faculty
J.V SIR

2. WHAT IS ALGORITHM?

3. Algorithm
 An algorithm is the finite set of sequential
instructions to accomplish a task where instructions
are written in a simple English language.
 It is called as a step by step solution of the program.
 It is a well developed, organized approach to solving
complex problems.
 It refers to logic of program.
 It is step by step solution to given program.

4. Characteristics of algorithm
 Algorithm has four characteristics:
 Finiteness : Total number of steps used in algorithm
should be finite.
 Definiteness : Each step of algorithm must be clear
and un ambiguous.
 Effectiveness : Every step must be basic and
essential.
 Input & output: the algorithm must accept zero or
more input and must produce at least one output.

5. How to develop an algorithm
 First identify different inputs to be given to system.
 Then identify what output you want from the
program.
 Then create logic for it.
 Break that logic into simple steps.
 Write this steps in order.
 This forms the algorithm required from the given
logic.

6. Advantages Disadvantages
 Very easy to write.
 Easy technique to
understand logic.
 Easy identification of
the mistakes by non
computer person.
 Time consuming.
 Difficult to show
branching and looping.
 Big tasks are difficult to
put in algorithm.

7. Write an algorithm to calculate area of
rectangle.
 Step 1: accept value of length i.e l
 Step 2: Accept the value of breadth i.e b
 Step 3: calculate area. i.e a=l*b
 Step 4: print area i.e Print a.
 Step 5: stop

8. Create a program to get name and roll
number from user and print it!
 Step 1: Initialize name as character and roll number
as integer
 Step2: Display message “ENTER NAME:” on screen
 Step 3: Get name from user
 STEP 4: Display message “ENTER R.NO:”
 Step 5: Get Roll number from USER
 STEP 6: clear the screen
 STEP 7: Print name on screen
 STEP 8: Print roll number on screen
 STEP 9: STOP

9. Write an algorithm to
determine a student’s final grade and
indicate whether it is passing or failing.
The final grade is calculated as the
average of four marks.
 Step 1: input a set of 4 marks
 Step 2: calculate average of marks
 Step 3: if avg <50 then go to next step else go to step
5.
 Step 4: print fail.
 Step 5: print pass.
 Step 6: stop

10. Write a algorithm to find out smallest
number out of two numbers.
 Step 1: Accept Two number I.e a,b
 Step 2: check if a<b? if yes go to step 3 else go to
step 5.
 Step 3: Print a is smallest number.
 Step 4: stop
 Step 5: print b is smallest number.
 Step 6 : stop

11. WHAT IS FLOWCHART?

12. What is a flowchart?
 It is a pictorial representation of the algorithm.
 What we did in algorithm, we can represent it in
flowchart.
 This format is easy to understand.
 It shows us the flow of the instructions.

13. Symbols of flowchart
Name Symbol Use in flowchart
Oval Used at starting and at
ending of the program.
Flowlines Used to show direction
of the flow.
Parallelogram Used for input output
options.
Rectangle Denotes process to be
carried out.

14. Symbols of flowchart
round
Diamond It is used for showing
decision structure.
Round Connecting flow lines
from different places
Block Indicates block of
statements or body of
loop

15. Advantages Disadvantages
 Easy to draw.
 Easy technique to
understand logic.
 Easy to identify the
mistake by non
computer person.
 Easy for branching and
looping.
 Time consuming.
 Difficult for modification.
 Difficult task to draw
flow charts for big
programs.

16. Different operators used in programing
 Determine how one value relates to another
 Equal to ==
 Not equal to !=
 Less than <
 Greater than >
 Less than or Equal to <=
 Greater than or Equal to >=

28. Example : write an algorithm and flowchart for
converting length in feet to centimeter.
 Algorithm:
 Step1: input l in ft
 Step 2: L in cm= l in ft*30
 Step 3: Print l in cm.
 Flowchart:
in ft
start
Read
value of l
L in cm= l in ft*30
Print l in cm
stop

29. Example: write an algorithm and flowchart to
read 2 sides of rectangle and calc. its area.
 Algorithm:
 Step1: read input W,L.
 Step2: A=W*L
 Step3: print A
 Flowchart:
 Read W,L
start
Read
value of W
& L
A= L*W;A = L * W
Print area
A
stop

30. Any questions?