Which of the following uses only increment operations for adding and removing…

Answer: Deques — a deque (double-ended queue) supports insertion and removal at both the front and the back.

Why this is correct:

• Definition: A deque allows adding and removing elements at both ends (front and back).

• Typical implementation note: Using a circular array with head and tail indices makes these operations efficient. Example index updates (modulo capacity): push_back increments the tail index, pop_back decrements the tail, push_front decrements the head, and pop_front increments the head. All index changes are simple pointer arithmetic.

• Why other structures are incorrect:

  • Queue: supports insertion at the rear and removal from the front only (FIFO), not both ends.

  • Stack: supports insertion and removal at a single end (the top) only.

  • Priority Queue: removal depends on element priority and requires comparisons and reordering (e.g., heap operations), not just simple end-based pointer updates.

Takeaway: The double-ended nature of deques is what enables adding and removing at either end; implementations use simple index arithmetic to make these operations efficient.