1. Algorithms Sheet 2 Identifying Control Structures

2. 1. Match the terms sequence, binary selection, multiway selection and iteration to the descriptions that follow: (a)a decision taken in an algorithm which can go either of two ways binary selection (b) decision taken in an algorithm which allows more than two choices multiway selection decision two decision more than two

3. 1. Match the terms sequence, binary selection, multiway selection and iteration to the descriptions that follow: (c)a decision taken in the processing done by an ATM to either withdraw, deposit or check account balance, depending on the key pressed multiway selection (d) a loop in a process which repeats the same instructions a number of times iteration decision more than two repeats

4. 1. Match the terms sequence, binary selection, multiway selection and iteration to the descriptions that follow: (e) a part of a program where we always add 1 to a counter and then print sequence (f)a portion of a program that is done over and over again, and only stops when the count reaches zero iteration always over and over again

5. 2. Identify two of the control structures used in each of the following algorithms (a) Count = 0 REPEAT DoTheLoop Add 1 to Count UNTIL Count = 5 sequence iteration/repetition sequence

6. 2. Identify two of the control structures used in each of the following algorithms (b) WHILE Count <= 5 Add 1 to Count DoTheLoop END WHILE iteration/repetition sequence

7. 2. Identify two of the control structures used in each of the following algorithms (c) Get NextVideo IF category = ‘X’ THEN print ‘You cannot watch this!’ ELSE DoBorrowProcess Print details END IF sequence selection (binary)

8. 2. Identify two of the control structures used in each of the following algorithms (d) REPEAT Enter Number IF Number > highest THEN set highest to Number END IF UNTIL no more Numbers iteration/repetition sequence selection

9. 2. Identify two of the control structures used in each of the following algorithms (e) WHILE more input Select input CASE 1 DoWithdrawals CASE 2 DoDeposits CASE 3 DoAccountBalance CASE other DoErrorProcess END select Get input END WHILE iteration/repetition selection (multiway) sequence

10. 3. Identify the control structure other than sequence used in the following algorithms:

14. Remember You need to know how to apply this information, so see me for further help if you think it is necessary for you.