Key Concepts

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Queue follows FIFO protocol

A queue is a data structure composed of nodes, which follows a first in, first out (FIFO) protocol.

This is analogous to a line at a grocery store, for which the first customer in the queue is the first to checkout.

Queue data structure methods

The queue data structure has three main methods:

  • enqueue (adds a node to the back of the queue)
  • dequeue (removes node at the front of the queue)
  • peek (returns value of node at the front of the queue, without removing it)
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Queues: Conceptual
Lesson 1 of 2
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  1. 1

    A queue is a data structure which contains an ordered set of data. Queues provide three methods for interaction: - Enqueue - adds data to the “back” or end of the queue - Dequeue - provides and re…

  2. 2

    Queues can be implemented using a linked list as the underlying data structure. The front of the queue is equivalent to the head node of a linked list and the back of the queue is equivalent to th…

  3. 3

    Let’s take a minute to review what we’ve covered about queues in this lesson. Queues: - Contain data nodes - Support three main operations: - Enqueue adds data to the back of the queue - Dequeue…

  1. 1

    As previously mentioned, a queue is a data structure that contains an ordered set of data that follows a FIFO (first in, first out) protocol. You can visualize it as a line at a deli: - The custome…

  2. 2

    Bounded queues require limits on the number of nodes that can be contained, while other queues don’t. To account for this, we will need to make some modifications to our […] class so that we c…

  3. 3

    “Enqueue” is a fancy way of saying “add to a queue,” and that is exactly what we’re doing with the […] method.

    There are three scenarios that we are concerned with when adding a node to the q…

  4. 4

    We can add items to the tail of our queue, but we remove them from the head using a method known as […] , which is another way to say “remove from a queue”. Like […] , we care about the size …

  5. 5

    Congrats! You have just implemented a queue data structure in Python by creating a […] class that: - follows FIFO protocol with […] , […] , and […] methods - gives you the option of …

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