How can I use advanced priority queues in C++11?

How can I use advanced priority queues in C++11?

In C++11, you can use the std::priority_queue class. It allows you to manage a collection of elements with a priority.

Can you show me an example of how to implement it?

Sure! Here's a simple example:

#include <queue>
#include <vector>
#include <iostream>

int main() {
    std::priority_queue<int> pq;
    pq.push(10);
    pq.push(5);
    pq.push(20);

    while (!pq.empty()) {
        std::cout << pq.top() << ' ';
        pq.pop();
    }
    return 0;
}

This will output: 20 10 5, as it retrieves elements in descending order.

What if I want to use a custom comparator?

You can define a custom comparator by creating a struct or a lambda function. For example:

struct CustomCompare {
    bool operator()(int a, int b) {
        return a > b; // Min-heap
    }
};

std::priority_queue<int, std::vector<int>, CustomCompare> minHeap;

This will create a min-heap instead of the default max-heap.

Are there any performance considerations I should be aware of?

Yes, priority queues are efficient for insertions and deletions, but if you need to access elements frequently, consider the underlying data structure. For large datasets, the choice of comparator can also impact performance.