priority queue in c++

A priority queue in C++ is a data structure that allows for efficient insertion and retrieval of elements based on their priority. It is implemented using a heap, which is a complete binary tree where each node satisfies the heap property.

To use a priority queue in C++, you need to include the <queue> header file. Here are the steps to create and use a priority queue:

  1. Declare a priority queue object: cpp std::priority_queue<int> pq; This declares a priority queue named pq that stores integers. You can replace int with any other data type you want to store.

  2. Insert elements into the priority queue: cpp pq.push(10); pq.push(20); pq.push(30); This inserts the elements 10, 20, and 30 into the priority queue. The elements are automatically ordered based on their priority.

  3. Retrieve the top element: cpp int topElement = pq.top(); This retrieves the top element of the priority queue (which has the highest priority) and assigns it to the variable topElement.

  4. Remove the top element: cpp pq.pop(); This removes the top element from the priority queue.

  5. Check if the priority queue is empty: cpp bool isEmpty = pq.empty(); This checks if the priority queue is empty and assigns the result to the variable isEmpty.

  6. Access the size of the priority queue: cpp int size = pq.size(); This retrieves the number of elements in the priority queue and assigns it to the variable size.

That's it! You now have a basic understanding of how to use a priority queue in C++. Feel free to explore the various member functions and customize the priority queue to suit your specific needs.