Actual 2025 AQA AS COMPUTER SCIENCE 7516/1 Paper 1 Merged Question Paper + Mark Scheme

Section A
You are advised to spend no more than 20 minutes on this section.
Enter your answers to Section A in your Electronic Answer Document. You must save this
document at regular intervals.
Question 04 in this section asks you to write program code starting from a new
program/project/file.
You are advised to save your program at regular intervals.
0 1 Figure 1
S1 ← "011101"
S2 ← "001100"
C ← "0"
R ← ""
FOR J = 0 TO 5
 X ← 5 - J
 D1 ← S1[X]
 D2 ← S2[X]
 IF C = "0" THEN
 IF D1 = D2 THEN
 S ← "0"
 C ← D1
 ELSE
 S ← "1"
 ENDIF
 ELSE
 IF D1 = D2 THEN
 S ← "1"
 C ← D1
 ELSE
 S ← "0"
 ENDIF
 ENDIF
 R ← CONCATENATE(S, R)
ENDFOR
OUTPUT R
The function CONCATENATE(X, Y) returns the string formed by concatenating the
string Y to the end of string X. For example, CONCATENATE("cat", "dog")
returns "catdog".
The strings are zero index based.