Part of a program's calculations uses the integer variables j, k, m, n and p. j = 3 k = 2 m = 10 n = (j + k)/(j - k) p = m * (m - j * k)

Mark scheme

Marking points from the official mark scheme (May/June 2022). The mark or mark type is shown in brackets.

1. [2] 5(a) One mark for each in order j k + j k - / j k + j k - /
2. [4] 5(b)(i) 1 mark per ring Do not allow operators in stacks [Stack states description: Start: []; 1. Push 10: [10]; 2. Push 10: [10, 10]; 3. Push 3: [10, 10, 3]; 4. Push 2: [10, 10, 3, 2]; 5. Operator '*': Pop 2, Pop 3 -> 6; Push 6: [10, 10, 6]; 6. Operator '-': Pop 6, Pop 10 -> 4; Push 4: [10, 4]; 7. Operator '*': Pop 4, Pop 10 -> 40; Push 40: [40]]
3. [4] 5(b)(ii) Any four from Max 4 Max 3 generic answer only • Working from left to right in the expression • PUSH 10/m onto the stack • PUSH the following numbers (10/m, 3/j, 2/k) onto the stack • When the first operator,*, is reached • POP the top two numbers, 2/k and 3/j • apply the operation • PUSH result back onto stack Continue to the end of the expression
4. [2] 5(c) Any two from • recursion • implementation of ADTs e.g. linked lists • procedure calls • interrupt handling (storing contents of registers etc)