A programmer implements the subroutine shown in Figure 1 to check if a username is containing a blacklisted phrase.
1 SUBROUTINE IsBlocked(user)
2 blacklist ← ['guest', 'temp', 'bot']
3 i ← 0
4 found ← false
5 WHILE i < 3
6 IF user = blacklist[i] THEN
7 found ← true
8 ENDIF
9 i ← i + 1
10 ENDWHILE
11 RETURN found
12 ENDSUBROUTINE
Figure 1
He replaces line 7 with:
RETURN true
He also replaces line 11 with:
RETURN false
Explain how the programmer has made the subroutine more efficient.
15 exam-style questions on AQA GCSE Computer Science Efficiency of algorithms. Each one has a worked solution and a mark scheme showing where the marks go.