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Aya Bouchiha
Aya Bouchiha

Posted on • Updated on

Queue Data Structure

Hi, today, we're going to discuss queue :)

Definition Of Queue

A Queue is a linear data structure that stores items in a First-In/First-Out (FIFO) manner. In Queue, the element that goes in first is the element that comes out first.

queue data structure

Space and Time complexity

the space complexity of a queue is O(n)

add ( enqueue ) remove (dequeue) search access
O(1) O(1) O(n) O(n)

Implementation of queue using python

class Queue:

    def __init__(self,size):
        self.items = []
        self.front = self.rear = 0 
        self.size = size
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def enqueue(self,data):
        if not self.isFull()  :
            self.rear += 1 
            return f'{self.items[-1]} added'
            return 'full'
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def dequeue(self):
        if not self.isEmpty() :
            self.rear -= 1 
            return 'deleted successfuly'
        return 'empty'
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    def isEmpty(self) -> bool:
        return  self.rear == self.front
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    def isFull(self) -> bool :
        return self.size == self.rear
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References and useful ressources

Have a good day!

Top comments (2)

rzaw profile image

Hello everyone. This is my first comment on this platform.

Could you provide some examples were this structure would be useful?

ayabouchiha profile image
Aya Bouchiha

Hi, this is a good quesion, we can use Queue in all kinds of customer service such as Call Center phone systems in banks or in big companies to hold people calling them in an order, until a service representative is free, in addition, It is used In operating systems, for controlling access to shared system resources like files, printers and disks,queue is used in routers or switches as well, however, it is used in many algorithmes like Round Robin Schedule, Breadth First Search .
Have a great day.