Implementing Priority Queue

# Introduction

In this lab, we will learn about the basic functionality of the Priority Queue in C++ programming language. Priority Queue is a container in C++ STL (Standard Template Library) that allows you to insert and remove elements according to their priority. The element with the highest priority is always placed at the front of the queue. When an element is removed from the queue, the priority queue automatically takes care of inserting the next highest priority element at its correct position.