Identifying Errors (Cambridge (CIE) IGCSE Computer Science)

An algorithm has been written in pseudocode to allow some numbers to be input. All the positive numbers that are input are totalled and this total is output at the end. An input of 0 stops the algorithm.

01 Exit ← 1
02 WHILE Exit <> 0 DO
03 INPUT Number
04 IF Number < 0
05 THEN
06 Total ← Total + Number
07 ELSE
08 IF Number = 0
09 THEN
10 Exit ← 1
11 ENDIF
12 ENDIF
13 ENDIF
14 OUTPUT "The total value of your numbers is ", Number

Identify the four errors in the pseudocode and suggest a correction for each error.

An algorithm has been written in pseudocode to calculate a check digit for a four-digit number. The algorithm then outputs the five-digit number including the check digit. The algorithm stops when –1 is input as the fourth digit.

01 Flag FALSE
02 REPEAT
03 Total 0
04 FOR Counter 1 TO 4
05 OUTPUT "Enter a digit ", Counter
06 INPUT Number[Counter]
07 Total Total + Number * Counter
08 IF Number[Counter] = 0
09 THEN
10 Flag TRUE
11 ENDIF
12 NEXT Counter
13 IF NOT Flag
14 THEN
15 Number[5] MOD(Total, 10)
16 FOR Counter 0 TO 5
17 OUTPUT Number[Counter]
18 NEXT
19 ENDIF
20 UNTIL Flag

Identify the three errors in the pseudocode and suggest a correction for each error.