3 marksAbstract Data Types (ADTs)

CAPE Computer Science Unit 2 · 2016 · Paper 2 · Question 1(c)

An empty queue Q of size 5 executes a sequence of operations: Line 1: Q.enqueue ('A'); Line 2: Q.enqueue ('B'); Line 3: Q.enqueue ('C'); Line 4: Char c = Q.dequeue ( ); Line 5: Q.enqueue ('A');

Draw diagrams showing the contents of the queue Q after executing Line 3, Line 4, and Line 5, showing all elements in the queue for each illustration.

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Other parts of this question

1(a)(i)Identify which data structure would be most appropriate for a call centre to ensure calls are answered in first-in, first-out order.[1 mark]
1(a)(ii)Identify which data structure would be most appropriate to allow the 'Undo' button to operate correctly in a word processing application.[1 mark]
1(a)(iii)Identify which data structure would be most appropriate to store an unknown number of data items and subsequently search for different keys.[1 mark]
1(b)Write code to implement the function `public void insertToFront(String s)` which accepts a string `s`, stores it in a new node, and inserts it at the front of…[3 marks]
1(d)Describe three operations that can be executed on a stack.[6 marks]
1(e)Write C code to reverse the order of items in a queue (e.g. from x1, x2, x3 ... xN to xN ... x3, x2, x1 where xN is at the front).[10 marks]

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