Question

What will be the position of front and rear after execution of the following statements, the Queue already had the given elements in FIFO order:
\(F→50 → 90 → 7 → 21 → 73 → 77→R\)
dequeue()
dequeue()
dequeue()
dequeue()
dequeue()
enqueue(100)
dequeue()

• A. Front 50, Rear 77
• B. Front 100, Rear 100
• C. Front 77, Rear 100
• D. Front 73, Rear 77

Answer 1

The Correct Option is C

Initial queue state: \(F \to 50 \to 90 \to 7 \to 21 \to 73 \to 77 \to R\).

Step-by-step operations:

1. dequeue(): Removes 50. Queue: \(F \to 90 \to 7 \to 21 \to 73 \to 77 \to R\).
2. dequeue(): Removes 90. Queue: \(F \to 7 \to 21 \to 73 \to 77 \to R\).
3. dequeue(): Removes 7. Queue: \(F \to 21 \to 73 \to 77 \to R\).
4. dequeue(): Removes 21. Queue: \(F \to 73 \to 77 \to R\).
5. dequeue(): Removes 73. Queue: \(F \to 77 \to R\).
6. enqueue(100): Adds 100. Queue: \(F \to 77 \to 100 \to R\).
7. dequeue(): Removes 77. Queue: \(F \to 100 \to R\).

After all operations, the queue is \(F \to 100 \to R\). The logical Front is 77 and the Rear is 100.

Correct Option: Front 77, Rear 100