Pendalaman Materi Conditional dan Repetition ( Pengulangan )

1. PendalamanMateri Conditional dan Repetition (Pengulangan)

2. IF THEN Bersarang Input (nilai) IF nilai > 85 AND nilai <= 100 THEN Output (‘Nilai mutu = A’) ELSE IF nilai > 60 AND nilai <= 85 THEN Output (‘Nilai mutu = B’) ELSE IF nilai > 45 AND nilai <= 60 THEN Output (‘Nilai mutu = C’) ELSE IF nilai > 30 AND nilai <= 45 THEN Output (‘Nilai mutu = D’) ELSE Output (‘Nilai mutu = E’) ENDIF ENDIF ENDIF ENDIF • The value variable of nilai = 60, the result is ‘Nilai mutu = B’. • The value variable of nilai = 101, the result is ‘Nilai mutu = E’. • The value variable of nilai = -5, the result is ‘Error’.

3. Write the algorithm to calculate cost of electricity with following constraints : (KWHs) Rate 0 - 500 2000 501 - 1000 2000 + 0.03 * per KWH under 500 over 1001 3500 + 0.02 * per KWH under 1000 • Enter the values of previous month meters, current month meter, and then displays the total cost which would exist.

4. Loops notation • While-Do-EndWhile • Repeat-Until,and • For-Do-EndFor,

5. WHILE-DO-ENDWHILE • it allows a {group of} program statement(s) to be executed a number of times. • The program statement(s) are executed when the condition evaluates as true. • Somewhere inside the loop the value of the variable which is controlling the loop (ie, being tested in the condition) must change so that the loop can finally exit.

6. The structure of the WHILE... DO... statement ... {initiation} WHILE (condition) DO program statement program statement … counter statement ENDWHILE ... • Counted loops are special types of pre-test loops. They are used when a known number of repetitions will occur. • condition is the Boolean Expression, whether it be AND, OR, or NOT, is first carried out. If the result is TRUE, the DO statement will then be performed. However, if the result is FALSE, the DO statement will not be executed • Iterationwill be controlled by Counter statement, wetherit be increase or decrease • The value of counter will be changed at the end of loop.

7. START {initiationi} condition = true? action {changing counter} END Flowchart WHILE... DO... No yes

8. Flowchart Pressure on mat? F T Sound bell Example 1 Pseudocode WHILE there is pressure on the mat Sound the bell ENDWHILE

9. Example 2 Pseudocode OUTPUT('before loop starts') i  0 { Initialize counter variable } WHILE (i <= 5) DO { Loop with predicate in ()} i  i + 1 {Increment counter variable} OUTPUT('iteration number ',i) ENDWHILE OUTPUT('after loop ends')

10. Execution • generates the output • Here, the loop predicate is the relational test "i <= 5", which causes the loop to terminate after i is incremented to six.

11. Example 3 i  0 {initialize} WHILE (i < 5) DO {number of iteration} Output (‘*’) {statement} i  i + 1 {increment counter} ENDWHILE The result of program : * * * * *

12. Example 4 • Program with enter the value of 3 student’s scores : Pseudocode i  1 WHILE i <= 3 DO Output (‘Score student no-‘,i,’ is:’) Input (score) i i + 1 ENDWHILE • Execution : • Score student no-1 is : __ • Score student no-2 is : __ • Score student no-3 is : __

13. Example 5 • Average of 3 numbers number  0 {initialize} count  3 {counters} WHILE count > 0 DO Input (x) {enter value of x} number  number + x {sum of x variables} count  count – 1 {decrement counter variable} ENDWHILE average  number/ 3 {calculate the average} Output (average)

14. REPEAT-UNTIL • Post-test loops tests the condition at the end of the loop. • The process in the loop is executed first whether it is true or false and will keep repeating until the condition is met. • Post-test loops end when the condition is true but the loop always do the loop at least once, even if the end condition is originally true. • Post-test loops are also called unguarded loops because no check is made before the algorithm begins the loop structure.

15. The structure of the REPEAT-UNTIL statement ... {initialize} REPEAT program statement counter variable UNTIL (condition) ...

16. START {initialize} MULAI Program statement {action} {inisialisasi} Counter changes aksi condition = true? END Flowchart REPEAT-UNTIL No yes

17. Example 1 Flowchart Pseudocode REPEAT Take out one item UNTIL bag is empty Take out item Is bag empty? F T

18. Example 2 Pseudocode OUTPUT('before loop starts') i  0 { Initialize counter variable } REPEAT i  i + 1 {Increment counter variable} OUTPUT('iteration number ',i) UNTIL (i= 5) { termination} OUTPUT('after loop ends')

19. Execution • generates the output

20. Example 3 i  0 {initialize} REPEAT Output (‘*’) {action statement} i  i + 1 {increment counter} UNTIL i=5 {end loop} The result of program : * * * * *

21. Example 4 • Program with enter the value of 3 student’s scores : Pseudocode i  1 REPEAT Output (‘Score student no-‘,i,’ is:’) Input (score) i i + 1 UNTIL i = 3 • Execution : • Score student no-1 is : __ • Score student no-2 is : __ • Score student no-3 is : __

22. Example 5 • Average of 3 numbers number  0 {initialize} count  3 {counters} REPEAT Input (x) {input value of x} number  number + x {sum of x variables} count  count – 1 {decrement counter variable} UNTIL count=0 average  number/ 3 {calculate the average} Output (average)

23. FOR-TO-DO • The statement inside the for block is executed a number of times depending on the control condition. • A loop index or loop counter is an integer variable that is used to keep track of how many times a loop has executed . • A loop limit is a variable or constant that is integer-valued, which determines the number of times a loop will execute, or a maximum value of the loop index to be reached at loop termination. . • A loop increment is the step size for incrementing the loop counter .

24. The structure of the FOR-TO-DO statement FOR counter variableinitial_valueTO final_value program statement ENDFOR

25. START {initialize} Counter >= initial_value AND counter <= final_value ? action END Flowchart FOR-TO-DO No yes

26. Example 1 Flowchart START Pseudocode FOR x1 TO 5 DO output (x) ENDFOR x >=1 AND x <= 5 ? No yes output (x) END

27. Example 2 Pseudocode OUTPUT('before loop starts') FOR i = 1 TO 5 DO OUTPUT('iteration number ',i) ENDFOR OUTPUT('after loop ends')

28. Execution • generates the output

29. Example 3 FOR i  1 TO 5 DO Output (‘*’) {action statement} ENDFOR {end loop} The result of program : * * * * *

30. Example 4 • Program with enter the value of 3 student’s scores : Pseudocode FOR i  1 TO 3 DO Output (‘Score student no-‘,i,’ is:’) Input (score) ENDFOR • Execution : • Score student no-1 is : __ • Score student no-2 is : __ • Score student no-3 is : __

31. Example 5 • Average of 3 numbers number  0 {initialize} FOR i  1 TO 3 DO Input (x) {input value of x} number  number + x {sum of x variables} ENDFOR average  number/ 3 {calculate the average} Output (average)

32. Contoh Nested Loop (pengulanganbersarang) FOR i  0 TO 4 DO FOR j  0 TO 2 DO Output (‘*’) {aksi} ENDFOR ENDFOR Program output : *** *** *** *** ***

33. Contoh Nested Loop (pengulanganbersarang) • Input values of 3 student’s score that have 2 different values FOR i1 TO 3 DO Output (‘Student score no-‘,i,’ are ’) FOR j1 TO 2 DO Output (‘Score ’,j,’ :’) Input (score) ENDFOR ENDFOR • Running : • Student score no- 1 are • Score, 1 : _ • Score, 2 : _ • Student score no- 2 are • Score, 1 : _ • Score, 2 : _ • Student score no- 3 are • Score, 1 : _ • Score, 2 : _

34. Soal 1 What are values of the variable x after the execution of the following pseudocode? n  0 x  0While n < 15 Do begin If (n mod 3) = 0 Then x  x + n Output(x)EndIf n  n +1 EndEndWhile • 1, 3, 6, 9, 12 • 0, 3, 6, 9,12 • 3, 18, 24 • 0, 3, 9,18, 30 • 3,6,9,12

35. Soal 2 Whatisthe output of thefollowingpseudocode? FOR i  1 TO 2 DO IF i mod 2 = 0 THEN FOR j  1 TO 4 DO IF j mod 2 = 1 THEN Output (‘x’) ELSE Output (‘o’) ENDFOR ELSE Output (i) ENDIF ENDFOR • i xoxo • xoxo i • i oxox • oxox i • i i

36. Soal3 Consider the following statement • INPUT : 7 • PROCESS : 1+2+3+4+5+6+7 • OUTPUT : 28 • Create your pseudocode

37. Soal4 • Determine the program of the following output, * ** *** ****

38. Soal5 • Determine the program of the following output, **** *** ** *

39. Soal 6 • What is the output of the following code {Declare} X,i : Integer Algorithm For X  1 to 10 IF (X mod 2= 0) THEN Output(X) i i + 1 ENDIF ENDFOR Output(i)

40. Soal 7 Describe the output of the following program for i 1 to 3 do for j 5 to 6 do Output(i,j) endfor endfor

41. Soal 8 • Write a program that it display the traditional song “Anak Ayam”. Enter the first anak ayam from keyboard.

42. Soal 9 • Write a program that display ‘*’ on even line and displays ‘#’ on odd line. Enter number of line from keyboard

43. Soal 10 • Write a program which outputs triangle numbers : 1, 3, 6, 10, 15, etc.

44. Soal 11 (nested loop) • Write a program which takes two integer values from the user and outputs the multiplication tables between the first and second numbers. (eg 4 and 7 will output the 4 times table, the 5 times table, the 6 times table and the 7 times table

45. Soal 12 • Write a program which validate a user password. If program accepts invalid password, the output will display “invalid password, try again!”, and then program request the password again until 3 times, after 3rd iteration, the output is ”unauthorized user” . The display to user who enter valid password is “wellcome”.

46. Soal 13 • Write a program which takes N integer values from the user and outputs the maximum. • Illustration • N = 3 • Data 1 : 15 • Data 2 : 20 • Data 3 : 10 • Maximum = 20