Q13Data Structures
Question
Write an algorithm to enqueue and dequeue an element in a queue.
Answer
A detailed algorithmic presentation of the Enqueue and Dequeue operational mechanics for a standard linear queue data structure implemented via an array.
A Queue is a fundamental linear data structure operating strictly on the First-In-First-Out (FIFO) principle. Elements are exclusively added at one terminal end (the REAR) and exclusively removed from the opposite terminal end (the FRONT). Assuming the queue is implemented using a static, zero-indexed array Q with a maximum capacity MAX, we require two tracking pointer variables: FRONT (initially -1) and REAR (initially -1).
1. The Enqueue Algorithm (Insertion)
The Enqueue operation inserts a newly provided data element VAL at the absolute rear of the queue structure. The algorithm must inherently protect against "Overflow" scenarios where the array is entirely full.
2. The Dequeue Algorithm (Deletion)
The Dequeue operation permanently extracts and returns the chronologically oldest data element currently residing at the front of the queue structure. The algorithm must vigorously protect against "Underflow" scenarios where the queue is entirely empty.