Step by Step solution about How to resolve the algorithm Priority queue step by step in the Java programming language

The provided Java source code defines a task scheduling program using a priority queue to handle tasks based on their priority levels. Here's a detailed explanation of the code:

1. Task Class:

• The Task class represents a single task with two properties:
  • priority: Denotes the priority level of the task (higher numbers indicate higher priority).
  • name: A string describing the task.

2. PriorityQueue:

• PriorityQueue<Task> pq = new PriorityQueue<Task>();: Creates a priority queue for managing tasks.
  • A priority queue is a queue structure where elements are ordered based on their priorities.
  • In Java, the PriorityQueue class implements the natural ordering of its elements (i.e., the Task objects) using their compareTo method.

3. Adding Tasks to the Queue:

• pq.add(new Task(3, "Clear drains"));: Adds a task with priority 3 and name "Clear drains" to the priority queue.
• Multiple tasks are added in a similar manner with different priorities and names.

4. Removing Tasks from the Queue:

• while (!pq.isEmpty()): Loops until the priority queue is empty.
• System.out.println(pq.remove());: Removes and prints the highest-priority task from the queue. In a priority queue, the highest-priority elements are always at the front of the queue and can be accessed using the remove method.

5. Overriding compareTo Method:

• The compareTo method is defined in the Task class to implement the comparison logic for the priority queue.
• It compares the priorities of two Task objects:
  • If the current task's priority is less than the other task's priority, it returns -1.
  • If the current task's priority is greater than the other task's priority, it returns 1.
  • If the priorities are equal, it returns 0.

Execution:

• When you run the program, it adds five tasks to the priority queue with varying priorities.
• Then, it repeatedly removes and prints the tasks from the queue until the queue is empty.
• The output will be a prioritized list of tasks printed in ascending order of their priorities.

In summary, this Java program demonstrates how to use a priority queue to implement a task scheduler based on priority levels. The priority queue ensures that tasks with higher priorities are processed first, making it useful for managing time-sensitive or critical tasks in various real-world applications.

import java.util.PriorityQueue;

class Task implements Comparable<Task> {
    final int priority;
    final String name;

    public Task(int p, String n) {
        priority = p;
        name = n;
    }

    public String toString() {
        return priority + ", " + name;
    }

    public int compareTo(Task other) {
        return priority < other.priority ? -1 : priority > other.priority ? 1 : 0;
    }

    public static void main(String[] args) {
        PriorityQueue<Task> pq = new PriorityQueue<Task>();
        pq.add(new Task(3, "Clear drains"));
        pq.add(new Task(4, "Feed cat"));
        pq.add(new Task(5, "Make tea"));
        pq.add(new Task(1, "Solve RC tasks"));
        pq.add(new Task(2, "Tax return"));

        while (!pq.isEmpty())
            System.out.println(pq.remove());
    }
}