Implementing a Queue

In this lesson, we will explore how to create and implement a queue data structure in C++. We will discuss the concept of a queue and its basic operations.

What is a Queue?

A queue is a linear data structure that follows the FIFO (First-In-First-Out) principle. It is similar to a real-life queue or line, where the first person to join the queue is the first one to be served.

Operations on a Queue

A queue supports two main operations:

1. Enqueue: This operation adds an element to the end of the queue.
2. Dequeue: This operation removes an element from the front of the queue.

Let's take a look at an example of implementing a queue in C++:

1#include <iostream>
2#include <queue>
3using namespace std;
4
5int main() {
6  // Create a queue
7  queue<int> q;
8
9  // Enqueue elements
10  q.push(10);
11  q.push(20);
12  q.push(30);
13
14  // Print front element
15  cout << "Front element: " << q.front() << endl;
16
17  // Dequeue elements
18  q.pop();
19  q.pop();
20
21  // Print front element
22  cout << "Front element: " << q.front() << endl;
23
24  return 0;
25}

In the code above, we include the <queue> header file to use the queue data structure in C++. We create a queue object q and perform operations like push to enqueue elements and pop to dequeue elements. The front function is used to retrieve the front element of the queue.

By implementing a queue, we can efficiently manage and process data in a first-in-first-out manner. In the upcoming lessons, we will explore more advanced concepts and operations related to queues.

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#include <iostream>

#include <queue>

using namespace std;

​

int main() {

  // Create a queue

  queue<int> q;

​

  // Enqueue elements

  q.push(10);

  q.push(20);

  q.push(30);

​

  // Print front element

  cout << "Front element: " << q.front() << endl;

​

  // Dequeue elements

  q.pop();

  q.pop();

​

  // Print front element

  cout << "Front element: " << q.front() << endl;

​

  return 0;

}