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Question 87

Complete the trace table for the algorithm shown in Figure 1 when the variable stream is given the following value from the user:

"HLLHLH"

You may not need to use every row in the table.

Figure 1

stream ← USERINPUT
buffer ← ""
FOR k ← 0 TO LEN(stream) - 1
    IF stream[k] = 'H' THEN
        buffer ← buffer + "1"
    ELSE
        buffer ← buffer + "0"
    ENDIF
    IF k MOD 3 = 2 THEN
        buffer ← ""
    ENDIF
ENDFOR

`stream`	`k`	`buffer`
`"HLLHLH"`

[3]

Markscheme

Representing algorithms Questions

GCSE
Computer Science
Representing algorithms

208 exam-style questions on AQA GCSE Computer Science Representing algorithms. Each one has a worked solution and a mark scheme showing where the marks go.

Representing algorithms

Question bank

Representing algorithms

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Question 87

Complete the trace table for the algorithm shown in Figure 1 when the variable stream is given the following value from the user:

"HLLHLH"

You may not need to use every row in the table.

Figure 1

stream ← USERINPUT
buffer ← ""
FOR k ← 0 TO LEN(stream) - 1
    IF stream[k] = 'H' THEN
        buffer ← buffer + "1"
    ELSE
        buffer ← buffer + "0"
    ENDIF
    IF k MOD 3 = 2 THEN
        buffer ← ""
    ENDIF
ENDFOR

`stream`	`k`	`buffer`
`"HLLHLH"`

[3]

Markscheme

Representing algorithms Questions

GCSE
Computer Science
Representing algorithms

208 exam-style questions on AQA GCSE Computer Science Representing algorithms. Each one has a worked solution and a mark scheme showing where the marks go.