1. Queue

• First In First Out (a line of people waiting for their turn)
• Insertion at the rear, Deletion at the front
• access to shared resources,(a printer), multiprogramming, auxiliary data structure for algorithms, component of other data structures

2. Operation

3. Implementation

Array-based Queue

Two variables to keep track

• f : index of the front element
• sz : number of stored elements

r : the index where you can insert a new element

= (f + sz) % N, N = the size of the array

4. Application

Round Robin Schedulers

• e = Q.dequeue() → Service element e → Q.enqueue(e)

4. ETC

• double-ended queue = deque : a queue where both insertion and deletion can be performed at both ends