2. ALGORITHMS
Algorithm: Is an ordered set of unambiguous, executable steps defining a terminating process
Unambiguous:during the execution of an algorithm, the information in the state of the process must be sufficient to determine uniquely and completely the action required by each step

3. ALGORITHMS Or
The execution of each step in an algorithm does not require creative skills. Rather, it requires only the ability to follow directions.

4. Control Structures
The key to clear algorithm design lies in limiting the control structure to only three structures:
Sequence, Selection, & Repetition
The following are the basic C and C++ control structures illustrated in flowchart and statement form:

5. 1) Sequence :
Example:
C=A+B

6. 2) Selection: if & if/else
if/else Structure(Double Selection)
if Structure (Single Selection) T F

7. 2) Selection: switch
Break T F
Switch Structure(Multiple Selection)

8. 3) Repetition: while & do/while
do/while structure T F
while Structure T F

9. 3) Repetition: for loop T F
for Structure

10. Pseudocode:
There are several ways to represent algorithms. Such as pseudocode, flowcharts, …
Pseudocode: Individual operations are described briefly and precisely in English standard statements consists of nouns and verbs

11. Pseudocode:
For example, to evaluate the formula for converting temperature reading from Celsius to Fahrenheit:
F= (9 /5) C + 32
Solution: Algorithm in pseudocode:
Get the value of C
Calculate F
Print F

12. While the flowchart used is shown bellow (the used control structure is Sequence ):
Start
Read C
F=(9/5)C+32
Print F
End

13. Example 1 : Write an algorithm and draw a flowchart to read the grades of five students , find the average of these grades and print it
Counter=1
total=0,average=0 If
Counter<5
Read Grade
Total=Total+grade
Average=Total/5
End
START T F
Print Average
Counter=Counter+1
Algorithm:
Initialize counter to 1
Initialize total to zero
Initialize average to zero
While counter is less than or equal 5
Input the grade
Add grade into total
average=total/5
Print average

14. Example2: A student took final exams of 10 courses
Example2: A student took final exams of 10 courses. Write an algorithm and draw a flowchart to read the grades and find their sum and print it.
START
Count=1
Total=0 If
Count<10
Read Grade
Print Total
Total=Total+Grade
END
Count=Count+1 T F
Algorithm:
Initialize Count to 1
Initialize Total to Zero
For Count=1 to 10
Read a Grade
Add Grade to Total
Print Total

15. Example 3 : Write an algorithm and draw a flowchart to read a grade, test it if PASS(more than or equal 50) or FAIL, and print the result .
START
Read Grade If
Grade>50
Print”PASS”
Print”FAIL”
END T F
Algorithm :
Read a Grade
If Grade more than or equal 50 Print PASS
Else Print FAIL