Question

Canvas Help Center ? Unanswered Question 4 0/3 pts Suppose we were to implement a queue using an array such that both enqeueue and dequeue have O(1) worst-case time complexity. Recall that to ensure con- stant time operations, we had to treat the array as circular. Assume that the front and rear markers begin at index 0. Suppose also that the queue has a fixed capacity of 5. That is, there is no array resizing done. Which choice be- low depicts the contents of the array after the following sequence of operations? (The array is shown frorn left to right beginning at index 0. The symbol is used to denote an empty cell.) q. enqueue (1); q. enqueue (2); q. enqueue (3); q. enqueue(4); q. dequeueO; q.dequeue ();q.dequeueO q.enqueue(5): q.enqueue (6); q.enqueue(7) q dequeue A. 05, 6, 7, ., ] Correct Answer

Why not A, who can help me?

Answer 1

after enqueue(1) queue is
1       *       *       *       *       

after enqueue(2) queue is

1       2       *       *       *       

after enqueue(3) queue is

1       2       3       *       *       

after enqueue(4) queue is

1       2       3       4       *       

after dequeue() queue is

*       2       3       4       *       

after dequeue() queue is

*       *       3       4       *       

after dequeue() queue is

*       *       *       4       *       

after enqueue(5) queue is

*       *       *       4       5       

after enqueue(6) queue is

6       *       *       4       5       

after enqueue(7) queue is

6       7       *       4       5       

after dequeue() queue is

6       7       *       *       5       

Now you can see why A can't be a solution.