What is a priority queue in C++?

What is a priority queue in C++?

A priority queue is an abstract data type that operates similarly to a regular queue but with an added feature: each element has a priority. Elements with higher priority are dequeued before those with lower priority.

How do I implement a priority queue in C++?

You can implement a priority queue in C++ using the STL priority_queue class. Here's a simple example:

#include <iostream>
#include <queue>

int main() {
    std::priority_queue<int> pq;
    pq.push(10);
    pq.push(20);
    pq.push(15);

    while (!pq.empty()) {
        std::cout << pq.top() << ' '; // Outputs: 20 15 10
        pq.pop();
    }
    return 0;
}

What are the differences between a priority queue and a regular queue?

The main difference is that in a regular queue, elements are processed in the order they arrive (FIFO), while in a priority queue, elements are processed based on their priority, regardless of the order they were added.

Can I use custom objects in a priority queue?

Yes, you can use custom objects in a priority queue by defining a comparison function or using a custom comparator to determine the priority of the objects.