4 This algorithm checks passwords. • Each password must be 8 or more characters in length; the predefined function Length returns the number of characters. • Each password is entered twice, and the two entries must match. • Either Accept or Reject is output. • An input of 999 stops the process. REPEAT OUTPUT "Please enter password" INPUT Password IF Length(Password) >= 8 THEN INPUT PasswordRepeat IF Password <> PasswordRepeat THEN OUTPUT "Reject" ELSE OUTPUT "Accept" ENDIF ELSE OUTPUT "Reject" ENDIF UNTIL Password = 999

Mark scheme

Marking points from the official mark scheme (May/June 2021). The mark or mark type is shown in brackets.

1. [1] Password column correctly filled with inputs in order: Secret, Secret, VerySecret, VerySecret, Pa55word, Pa55word, 999 (excluding prompt for each input)
2. [1] PasswordRepeat column correctly filled with inputs in order: (empty), (empty), VerySecret, (empty), Pa55word, (empty), (empty) (excluding prompt for each input)
3. [1] OUTPUT column correctly filled with outputs in order: (Please enter password), Reject, (Please enter password), Reject, (Please enter password), Accept, (Please enter password), Accept, (Please enter password), Reject
4. [1] Any four from: Position: before INPUT PasswordRepeat // at start
5. [1] ...use a (variable) counter (for number of tries) or flag
6. [1] ... initialise variable counter or flag
7. [1] Position after IF Length(Password) >= 8 THEN or after INPUT PasswordRepeat
8. [1] ... insert REPEAT/WHILE/(conditional) loop
9. [1] Position after OUTPUT "Reject"
10. [1] ... add one to counter (for number of tries)
11. [1] ... output a message "Try again"
12. [1] ... add INPUT PasswordRepeat
13. [1] Position after OUTPUT "Accept"
14. [1] [1] ... reset flag to show password matched
15. [1] Position after ENDIF
16. [1] ... (insert UNTIL/ENDWHILE) to exit the loop after three tries or if the repeated password matches the original