Priority Queue Data Structure in JavaScript 🚀

A simple implementation of the Priority Queue data structure in JavaScript. This repository demonstrates how to create a priority queue class with essential methods and explains its functionality with practical examples.

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What is a Priority Queue?

A Priority Queue is a data structure that stores elements in a way that allows efficient access to the element with the highest priority. Each element in the queue is assigned a priority value, and elements with higher priority are dequeued before elements with lower priority. Priority queues are commonly implemented using heaps.

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Features

• Enqueue: Add an element to the queue with a given priority.
• Dequeue: Remove and return the element with the highest priority.
• Peek: View the element with the highest priority without removing it.
• isEmpty: Check if the queue is empty.
• Size: Get the number of elements in the queue.

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Code Implementation

Here’s the JavaScript implementation of the priority queue:

class PriorityQueue {
    constructor() {
        this.queue = [];
    }

    // Add an element to the queue with a given priority
    enqueue(element, priority) {
        const item = { element, priority };
        if (this.isEmpty()) {
            this.queue.push(item);
        } else {
            let added = false;
            for (let i = 0; i < this.queue.length; i++) {
                if (item.priority > this.queue[i].priority) {
                    this.queue.splice(i, 0, item);
                    added = true;
                    break;
                }
            }
            if (!added) {
                this.queue.push(item);
            }
        }
    }

    // Remove and return the element with the highest priority
    dequeue() {
        if (this.isEmpty()) {
            return "Queue is empty!";
        }
        return this.queue.shift();
    }

    // View the element with the highest priority without removing it
    peek() {
        if (this.isEmpty()) {
            return "Queue is empty!";
        }
        return this.queue[0];
    }

    // Check if the queue is empty
    isEmpty() {
        return this.queue.length === 0;
    }

    // Get the size of the queue
    size() {
        return this.queue.length;
    }
}

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Example Usage

// Initialize the priority queue
const pq = new PriorityQueue();

// Enqueue elements with priorities
pq.enqueue("Task 1", 1);
pq.enqueue("Task 2", 3);
pq.enqueue("Task 3", 2);

// Peek at the highest priority element
console.log(pq.peek()); // Output: { element: 'Task 2', priority: 3 }

// Dequeue elements
console.log(pq.dequeue()); // Output: { element: 'Task 2', priority: 3 }
console.log(pq.dequeue()); // Output: { element: 'Task 3', priority: 2 }

// Check if the queue is empty
console.log(pq.isEmpty()); // Output: false

// Get the size of the queue
console.log(pq.size()); // Output: 1

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Real-World Applications

1. Task Scheduling: Managing tasks based on priority in operating systems.
2. Dijkstra's Algorithm: Finding the shortest path in graphs.
3. Job Scheduling: For scheduling jobs with different priorities in computers.
4. Bandwidth Management: Prioritizing network traffic based on importance.

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TikTok Tutorial 🎥

Want to see a quick tutorial on how to build this? Check out this TikTok video:

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How to Run the Code

1. Clone the repository:

   git clone https://github.com/fix2015/structure_priority_queue
   cd structure_priority_queue

2. Open the file index.js in your favorite code editor.
3. Run the file using Node.js:

   node index.js

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Contributing

Contributions are welcome! If you have suggestions or want to add new features, feel free to create a pull request.

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License

This project is licensed under the MIT License.

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