queue in c++

To implement a queue in C++, you can use the built-in container class std::queue from the Standard Template Library (STL). Here are the steps to create and use a queue in C++:

  1. Include the necessary header file:

cpp #include <queue>

  1. Declare a queue object:

cpp std::queue<int> myQueue;

In this example, we declare a queue named myQueue that can store integers. You can replace int with any other data type you want to use.

  1. Push elements into the queue:

cpp myQueue.push(10); myQueue.push(20); myQueue.push(30);

This code snippet adds elements 10, 20, and 30 to the queue using the push() function.

  1. Check the front element of the queue:

cpp int frontElement = myQueue.front();

The front() function returns the value of the front element of the queue, which is 10 in this case.

  1. Check the size of the queue:

cpp int queueSize = myQueue.size();

The size() function returns the number of elements currently present in the queue, which is 3 in this case.

  1. Check if the queue is empty:

cpp bool isEmpty = myQueue.empty();

The empty() function returns true if the queue is empty, and false otherwise.

  1. Pop elements from the queue:

cpp myQueue.pop();

The pop() function removes the front element from the queue.

These are the basic steps to create and use a queue in C++ using the std::queue class from the STL. Remember to include the necessary header file, declare the queue object, use the appropriate functions to push, access, and remove elements, and check the size and emptiness of the queue as needed.