1. Example # 1 Draw a flowchart for calculating the area of a room:
In order to calculate the area of the room, we must know firstly the length and the width of the room. Then we calculate the area by multiplying the length by width.

2. Goal: calculating the area of the room.
Input: length and width.
Process: area = length * width.
Output: area.

3. C code: don’t worry about it now
#include<stdio.h>
void main()
{ int length, width, area;
scanf("%d",&lendth);
scanf("%d", & width);
area = length * width;
printf("%d",area); }
Flowchart
START
Input length
Input width
area = length * width
Output area
END

4. The following flowchart is in correct. Can you guess why?
START
Input length
Input width
area = length * width
END
Output area

5. It is wrong because we cannot calculate the area of the room before knowing the length and width of the room. So, we should input the length and width of the room then calculate area.

6. Example # 2
Draw a flowchart which reflects the process of deciding whether a student has passed or failed . the course based on the average three exams.

7. Goal: decide whether the student pass or failed the course.
Input: m1, m2, m3 /*m mass mark */
Arithmetic Process:
sum = m1 + m2 + m3.
average = sum/3.
Logical process: is the average greater or equal to 60.
Output: passed or failed.

8. C code:don’t worry about it now
#include<stdio.h>
void main()
{ int m1, m2, m3;
Int sum, avg;
scanf("%d%d%d", &m1,&m2,&m3);
sum = m1 + m2 + m3;
avg = sum/3;
if(avg >=60) {
Printf("passed"); }
else
Printf("faild");
Flowchart
START
Input m1,m2,m3
sum = m1+m2+m3
avg = sum/3
YES Is
avg>=60 NO
Output “passed”
Output “failed”
END

9. Example # 3
Draw a flowchart which reflects the process of calculating the sum of 5 values:
Goal: calculate the sum of 5 values.
Input: value
Process: adding the values to each other.
Output: the sum

10. C code: don’t worry about it now
Flowchart
C code: don’t worry about it now
#include<stdio.h>
void main()
{ int value, sum, counter;
sum = 0;
counter = 1;
while(counter<=5) {
scanf("%d",& value);
sum = sum + value;
counter = counter + 1; }
printf("%d",sum);
START
Sum = 0
counter = 1 Is
Counter<=5
YES NO
Input value
sum =sum + value
counter = counter + 1
Output sum
END

11. Questions?
What would happen if the process counter = counter +1 did not exist?
What would happen if the process sum =0 did not exist?

12. Example # 4
Draw a flowchart for finding the maximum value of 10 input values.
Goal: finding the maximum value.
Input: value
Process: comparing to find the maximum value.
Output: the maximum value

13. Flowchart START Input value max = value counter = 1 Is Counter<=10
C code:don’t worry about it now. #include<stdio.h> void main() { int value, max, counter; scanf("%d", & value); max = value; counter = 1; while(counter<=10) { scanf("%d", &value); if(value>max) } counter = counter + 1; printf("The maximum is %d \n ",max);
Flowchart
START
Input value
max = value
counter = 1 Is
Counter<=10 NO
YES
Input value Is
Value>max NO
YES
max = value
counter = counter + 1
Output max
END