What is a flowchart, advantages, disadvantages, exercises

1. Flowcharts
Mukesh N.Tekwani
IsmailYusuf College of
Arts, Science and Commerce,
Jogeshwari (East),
Mumbai
tekwani@email.com
Presented at the One DayWorkshop Organized by K.P.B. Hinduja College
of Commerce, University of Mumbai on the Semester-wise splitT.Y.B.Com
and S.Y.B.Com Computer papers on
July 20, 2013

2. What is a Flowchart?
 What is a flowchart?
◦ Graphical or pictorial representation of an
algorithm or problem solving process
 Flow?
◦ Indicates the flow of logic, or sequence of
steps.
◦ There is a ‘before’ step and an ‘after’ step
◦ Flow control is needed because programs are
not linear or top-to-down
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3. Why flowchart is useful?
 A picture is worth a thousand words
 Help in understanding complicated logic
 Language-independent and so easy to write
program in various languages
 Good tool for documentation
◦ Verbose syntax of certain languages is difficult to
understand; flowchart eliminates the need to know
syntax to understand the logic
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4. What can a Flowchart Represent?
 Sequential statements – assignment,
calculations, input & output
 Branching or Selection Statements – if-then,
if-then-else: using Decision Symbol
 Looping Statements – for, while loops
 Switch-Case statement (successive decision
symbols)
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5. Symbols used in Flowcharts
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6. Guidelines in Drawing a Flowchart
 Logical sequence
 Standard symbols
 Direction of flow  top-to-down
◦ To jump to a step further down, go from right
◦ To jump to a step above the current step, go
from left
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7. Guidelines in Drawing a Flowchart
 Only one flow line should enter a decision
symbol
 More than one flow line may leave a symbol
 Only one flow line used with Stop symbol
 Use connector symbol to breakup a
complex flowchart
 A flowchart must end with the Stop
statement
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8. Flowchart of ‘while’ loop
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9. Flowchart of ‘for’ loop
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10. Flowchart of ‘if’ statement
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11. Flowchart of ‘if-else’ statement
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12. Flowchart of ‘switch-case’ statement
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13. Sum of Two Numbers
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14. START
INPUT X, Y
Is X > Y ?
BIG = X
Yes
PRINT BIG
BIG = Y
STOP
No
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s
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15. F
a
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i
a
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o
f
a
N
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b
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Yes
START
Read N
F = 1
M = 1
Is
M = N?
F = F * M
Print F
No
M = M + 1
STOP
Assume:
N  no. whose factorial is
required
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16. MultiplicationTableofanumberinputby
user
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17. Flowchart – Find the Largest of Three Numbers
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18. Limitations of Flowcharts
 Complex – for lengthy algorithms, flowchart
can be very large  difficult to follow
 Time-consuming – drawing complex
flowcharts can be very time-consuming
 Modification – difficult to modify; redraw
entire flowchart
 Update – program update is easier; not so
for flowcharts  redraw flowchart !
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19. Exercise
 Design an algorithm and the corresponding
flowchart for finding the sum of the numbers
2, 4, 6, 8, …, n
 Draw a flowchart to read 100 numbers and
then display the sum
 Draw a flowchart to display all odd numbers
between 0 and 1000
 Draw a flowchart to find the sum of first 10
natural numbers and then display the sum
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20. Suggestions
 Algorithm  Flowchart  Program
 Use programs in C language to develop
questions on Algorithms and Flowcharts
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21. THANK YOU
STOP
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