Question

Suppose the letter A is placed in an empty queue, followed by the letters B and C, in that order. Then suppose that a letter is removed from the queue and the letters D and E are inserted. List the letters that would be in the queue in the order they would appear from head to tail. If a letter is now removed from the queue, which letter will it be?

Answer 1

Queue:

Queue works on FIFO rule ( First In First Out ) . The element which is entered first will be deleted first. Queue has mainly two operations.

Enqueue : Inserting element from top

Dequeue : Deleting element from bottom / Start point

1) So first A is entered and then B, C are inserted at top of it. and if we have to remove a letter we have to remove it from bottom. i.e A in below example.

2) Later D and E are inserted

Now the queue is in order B, C, D, E

3) After removing a element

Now order of queue is C, D, E