Linear Data Structure • FIFO Model

Regular Queue Visualization

A linear sequential collection governed by the First-In, First-Out (FIFO) principle. Elements enter at the rear (tail) and depart from the front (head).

Abstract Data Type Properties

Queues emulate standard waiting lines: arrival occurs strictly at the back, while service takes place at the front. Core real-world applications include OS process scheduling (CPU ready queue), IO buffering, print spooling, and BFS graph traversal.

Discipline
FIFO (First-In, First-Out)
Enqueue / Dequeue
O(1) Constant Time
Pointers
Front (Head) & Rear (Tail)

Operations Panel

1. Queue Sizing & Reset
2. Enqueue / Dequeue Mutations
3. Queue Inspection
FIFO Buffer Stage (Front → Rear)

Educational Reference

Enqueue(x)

Appends value x to the rear end of the queue. Fails if maximum allocated capacity is reached.

Dequeue()

Removes and returns the front element. Fails with an underflow error if the queue is empty.

Peek() / Rear()

Read-only inspections of the extreme elements (front index 0 or rear index n-1) without mutation.

Array Limitations

Linear static array queues without cyclic wrap-around can cause wasted space after repeated dequeues.