Data-Structures

Consider the queues Q 1 containing four elements and Q 2 containing none (shown as the Initial State in the figure). The only operations allowed on these two queues are Enqueue(Q,element) and Dequeue(Q). The minimum number of Enqueue operations on Q 1 required to place the elements of Q 1 in Q 2 in reverse order (shown as the Final State in the figure) without using any additional storage is___________.