1. Representing an algorithm using Flowcharts
Review: Algorithms are step-by-step definitions given to solve a problem

2. Flowcharts
Many of us find it easier to follow steps when they are represented diagrammatically or graphically.
Flowchart shapes are:
terminators symbol(start or stop)
process symbol(assignments, calculations)
input/output symbols (read, write)
decision symbol(decisions between 2 options)
flow control- flow of steps
connector symbol(used to connect sections of a flowchart

3. Flowchart algorithm1 Write a pseudocode algorithm and a flowchart to find and display the sum of 10 and 20
Start a10 b20 Suma + b Print Sum stop
start
a10
b 20
suma + b
Print sum
stop

4. Flowchart algorithm2 Draw a flowchart that will read 3 numbers and find the product of the 3 numbers
Start Read n1, n2, n3 Productn1*n2*n3 Display product stop
start
Read n1,n2,n3
Productn1*n2*n3
Print product
stop

5. Flowchart algorithm3 Draw a flowchart that will accept 3 numbers and find and display their average
Start Read n1,n2,n3 Average(n1+n2+n3)/3 Write average stop
start
Read n1,n2,n3
Average (n1+n2+n3)/3
Write average
stop

6. Write “Enter 2 unequal numbers”
Flowchart algorithm4 Draw a flowchart that will prompt the user to enter 2 unequal numbers and find the largest between them.
start
Start Write “Enter 2 unequal numbers” Read n1,n2 If n1>n2 then set largen1 else set largen2 Endif Print large stop
Write “Enter 2 unequal numbers”
Read n1,n2
yes
Is n1>n2 no
Largen1
Largen2
Write large
stop

7. Flowchart algorithm4 Draw a flowchart that will prompt the user to enter 3 unequal numbers and find the smallest among them.
Start Write “Enter 3 unequal numbers” Read num1,num2,num3 If num1<num2 then smallnum1 else small num2 Endif If num3<small then smallnum3 Write small stop
Flowchart solution on next slide

8. Write “enter 3 unequal numbers
start 1
Write “enter 3 unequal numbers
Is num3<small
yes no
Read num1,num2,num3
Smallnum3
Is num1<num2 no
yes
Write small
For additional and more complex questions see Heinemann, page 96 (flowcharts with unbounded iteration) to page99 (flowcharts with bounded iteration)
Stop
Smallnum1
Smallnum2 1

9. Question
A problem requires you to read 3 numbers and calculate and print the total.
Construct:
IPO chart
Pseudocode
Flowchart