An algorithm has been written in pseudocode to check that a password meets a set of rules. 01 OUTPUT "Please enter password " 02 INPUT Password 03 Accept ← TRUE 04 IF LENGTH(Password) < 8 OR LENGTH(Password) > 20 05 THEN 06 Accept ← FALSE 07 ENDIF 08 IF LCASE(Password) = Password OR UCASE(Password) = Password 09 THEN 10 Accept ← FALSE 11 ENDIF 12 Index ← 1 13 Found ← FALSE 14 WHILE NOT Found AND Accept AND Index < LENGTH(Password) 15 IF SUBSTRING(Password, Index, 1) = '!' 16 THEN 17 Found ← TRUE 18 ENDIF 19 Index ← Index + 1 20 ENDWHILE 21 IF NOT Found 22 THEN 23 Accept ← FALSE 24 ENDIF 25 IF Accept 26 THEN 27 OUTPUT "Accepted" 28 ELSE 29 OUTPUT "Rejected" 30 ENDIF

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2024). The mark or mark type is shown in brackets.

1. [6] (a) For each trace table, one mark Password and output, one mark Accept, Index and Found columns
2. (a) MYWORD Trace Table: Password: MYWORD Accept: TRUE, FALSE, FALSE, FALSE Index: (blank), (blank), 1, (blank) Found: (blank), (blank), FALSE, (blank) OUTPUT: (Please enter password), (blank), (blank), Rejected
3. (a) M!word Trace Table: Password: M!word Accept: TRUE, FALSE, FALSE, FALSE Index: (blank), (blank), 1, (blank) Found: (blank), (blank), FALSE, (blank) OUTPUT: (Please enter password), (blank), (blank), Rejected
4. (a) My!Hidden Trace Table: Password: My!Hidden Accept: TRUE, TRUE, TRUE, TRUE, TRUE, TRUE Index: (blank), (blank), 1, 2, 3, 4 Found: (blank), (blank), FALSE, FALSE, TRUE, TRUE OUTPUT: (Please enter password), (blank), (blank), (blank), (blank), Accepted
5. [3] (b) One mark for each correct point
6. (b) maximum length 20 characters and minimum length 8 characters
7. (b) cannot be all upper-case letters or all lower-case letters // must contain upper-case and lower-case letters
8. (b) must contain an !