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

The final positions of front and rear after executing the queue operations will be Front 77, Rear 100.

Additional Context:

• Initial Queue State:
  • Front (F) → 50
  • Rear (R) → 77
  • Order: 50 → 90 → 7 → 21 → 73 → 77
• Operation Breakdown:
  1. dequeue() → Remove 50 → Queue: 90 → 7 → 21 → 73 → 77
  2. dequeue() → Remove 90 → Queue: 7 → 21 → 73 → 77
  3. dequeue() → Remove 7 → Queue: 21 → 73 → 77
  4. dequeue() → Remove 21 → Queue: 73 → 77
  5. enqueue(100) → Add 100 → Queue: 73 → 77 → 100
  6. dequeue() → Remove 73 → Queue: 77 → 100
• Final State:
  • Front points to 77 (next to dequeue)
  • Rear points to 100 (last added)
• Queue Properties:
  • FIFO (First-In-First-Out) structure
  • enqueue adds to rear, dequeue removes from front

Correct Answer: (3) Front 77, Rear 100.