Include Iostream, Fstream, String, And Cstring

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Alter your priority queue so it maintains priority using a Selection Sort. The highest priority should be given to nodes with larger values (ordered largest to smallest). Basically, sort your Priority Queue using a Selection Sorting algorithm each time the enqueue function is called. The priority queue should be written using a C++ class, named PQueue, and the queue itself should be implemented as a linked list. The following classes should be defined by your program: class Person : Used to store information about each person class PQueue : Priority queue used to serve people The following public functions need to be implemented: Person::Person( int, string ): Initialize the person PQueue::PQueue( void ) : Initialize the priority queue bool PQueue::empty( void ) : Test whether queue is empty int PQueue::size( void ): Return size Person PQueue::front( void ): Access next node Person PQueue::back( void ): Access last node void PQueue::enqueue( Person* ) : Insert node void PQueue::dequeue( void ) : Remove node The following private functions need to be implemented: void sort( void ): Sort linked list using selection sorting algorithm

Paper For Above instruction

The assignment aims to modify a C++ priority queue implementation so that it maintains its elements ordered by priority using a selection sort algorithm each time an element is enqueued. The key is to ensure that the highest priority, represented by larger numerical values, always comes first, and the queue is sorted in descending order. This problem involves designing classes, manipulating linked lists, and implementing a selection sort algorithm on linked list data structures.

The core classes involved are the 'Person' class, which stores each individual's data, and the 'PQueue' class, which manages the collection of Person objects as a linked list. The 'Person' class includes data members for the person's name and priority, with appropriate constructors and getter functions. The 'PQueue' class manages nodes with functions like enqueue, dequeue, and private sort to reorder nodes based on priority.

In this solution, the 'Person' class is implemented with an integer priority and a string name. Constructor initializes these members, and getter functions return their values. The 'printName' method outputs the person's name, using character array copying to demonstrate string manipulation with C-style functions like 'strncpy'.

The 'PQueue' class is implemented as a linked list with pointers to the front and back nodes, and a counter for size. The enqueue function inserts a new node into the linked list. After each insertion, the sort function is called to reorder the list in descending order based on priority. The sorting utilizes the selection sort algorithm adapted for linked list, by repeatedly finding the maximum element and swapping node data or pointers.

The 'dequeue' function removes the node at the front of the list, effectively serving the highest-priority person. It also outputs who is currently being served.

In the main function, the program reads data from a file ('sample.txt') which contains pairs of integers and strings representing the priority and name of each person. For each entry, a new Person object is created and enqueued. After all insertions, the queue is dequeued to serve each person, which includes printing the person's name as they are served.

This approach ensures the priority queue is reconstructed with each insertion, maintaining the order of nodes so that the highest priority is always at the front, complying with the selection sort strategy. Efficiency can be improved in future iterations, but for conceptual clarity, re-sorting after each insertion is a straightforward method.

The implementation demonstrates foundational principles of linked list manipulations, class design, and sorting algorithms in C++, aligned with object-oriented programming best practices. It addresses the critical tasks of maintaining an ordered priority queue, reading data from external files, and serving elements in priority order, fulfilling the specific requirements of the assignment.

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