Identifying Errors (Cambridge (CIE) IGCSE Computer Science)

An algorithm has been written in pseudocode to input some numbers. It only outputs any numbers that are greater than or equal to 100. The number 999 is not output and stops the algorithm.

INPUT Number
WHILE Numbers <> 999 DO
   IF Number > 100
      THEN
         OUTPUT Number
   ENDIF
ENDWHILE
OUTPUT Number

Identify the four errors in the pseudocode and suggest corrections.

Write a pseudocode statement to change the corrected algorithm to output all numbers between 100 and 200 inclusive.

You do not need to rewrite the whole algorithm

This section of program code asks for 80 numbers between 100 and 1000 inclusive to be entered. The pseudocode checks that the numbers are in the correct range and then stores the valid numbers in an array. It counts how many of the numbers are larger than 500 and then outputs the result when finished.

01 Count ← 0
02 FOR Index ← 1 TO 80
03 INPUT "Enter a number between 100 and 1000 ", Number
04 WHILE Number <= 99 AND Number >= 1001
05 INPUT "This is incorrect, please try again", Number
06 ENDWHILE
07 Num[80] ← Number
08 IF Number > 500 THEN Count ← Count + 1 ENDIF
09 UNTIL Index = 80
10 PRINT Index
11 PRINT "numbers were larger than 500"

There are four lines of code that contain errors.

State the line number for each error and write the correct code for that line.