What are priority queues and how are they implemented in different programming languages?

What are priority queues and how do they work?

Priority queues are abstract data types where each element has a priority. Elements with higher priority are served before those with lower priority.

Can you show me how to implement a priority queue in Python?

Sure! In Python, you can use the heapq module to implement a priority queue. Here's a simple example:

import heapq

class PriorityQueue:
    def __init__(self):
        self.elements = []

    def is_empty(self):
        return not self.elements

    def put(self, item, priority):
        heapq.heappush(self.elements, (priority, item))

    def get(self):
        return heapq.heappop(self.elements)[1]

How does this differ in Java?

In Java, you can use the PriorityQueue class from the java.util package. Here's a quick example:

import java.util.PriorityQueue;

class Main {
    public static void main(String[] args) {
        PriorityQueue<Integer> pq = new PriorityQueue<>();
        pq.add(5);
        pq.add(1);
        pq.add(3);
        while (!pq.isEmpty()) {
            System.out.println(pq.poll());
        }
    }
}