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:
Declare a priority queue object:
cpp std::priority_queue<int> pq;
This declares a priority queue namedpq
that stores integers. You can replaceint
with any other data type you want to store.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.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 variabletopElement
.Remove the top element:
cpp pq.pop();
This removes the top element from the priority queue.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 variableisEmpty
.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 variablesize
.
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.