Question

****NEED CODED IN C++, READ THE INSTRUCTIONS CAREFULLY AND PAY ATTENTION TO THE INPUT FILE, IT IS REQUIRED FOR USE IN THE PROBLEM****

You are to generate a list of customers to serve based on the customer’s priority, i.e. create a priority queue/list for a local company. The company has been receiving request and the request are recorded in a file, in the order the request was made. The company processes each user based on their priority, the highest priority which is the largest number. Priorities of equal value are first come first served as listed in the input file.  

Your input is a collection of customer IDs and priority, one per line.  

You are to read in the data and insert new data into a sorted linked list. The linked list is sorted by priority.

A customer may need an update on his order. He may submit a request a second time in order to change his priority level. If so, you will search the linked list, change the priority and adjust the new order in the sorted link list.

Input file: Priority Queue.txt

Output: List of ID’s with priorities in priority order

Example input:

1345 4

8243 1

Example output:

Customer Processing Order

Customer ID Priority

4124 5
1345 4

….    ….

Restrictions: Use an ordered link list for the data structure and a nice formatted print out.

INPUT FILE (NECESSARY TO IMPORT THE DATA INTO THE PROGRAM, NEEDS TO BE USED WITH IFSTREAM)

Priority Queue.txt

1432 2
8234 3
2124 5
8123 2
1314 2
1432 4
7141 3
7123 4
5523 1
6543 2
1731 5
3813 4
7213 5
3318 5
7213 3
7131 2
8882 3
9974 1
7221 3
7342 4
5523 3
3113 5
7002 4
9769 1
3145 5
7145 3
8834 2
9123 4
7878 1
7588 4
2025 1
6069 3
2025 3

The instructions can be translated as follows:

The objective is to make a priority queue/list.

The requests made to fill this queue include a 4-digit customer number and priority level ranging from 1 through 5.

This information is stored in a file.

If 2 customers have the same prio level, then the one that comes first in the list is treated as higher prio.

(first come, first serve basis)

I need to read in Priority Queue.txt to a sorted linked list. (sorted by prio)

I also need to insert new data into this linked list based on user input.

The input is based on a user being able to submit a 2nd request by entering their ID to change their prio level.

I can assume that when they do this, they bump their priority by 1. This is assumed because this program would serve no real function if every customer could just send another request and automatically be prio-5 or set that themself.

In this case, you want to search the Linked List, find the customer ID, change the prio, and adjust the new order in the sorted Linked List.

An ordered Linked List must be used for the data structure, and the output must be formatted neatly.

For input, this program will port in Priority Queue.txt for data.

For output, the program will display the Customer IDs in order of priority, keeping the FCFS rule in mind.

It will then prompt a user to be able to input their Customer ID for another request, bumping their prio by 1, re-sorting the LL, then outputting the new list.

Again, this is CODED IN C++ AND USES THE INPUT FILE FOR DATA.

Answer 1

#include <iostream>
#include <utility>
#include <fstream>

using namespace std;

class Node {
public:
        pair <int, int> data ;
        Node* next;
};

void display(Node* head)
{
        while (head != NULL)
        {
                cout << head->data.first << " " << head->data.second << "\n";
                head = head->next;
        }
}
void update_list(Node* head, int customerId, int priority)
{
    // This function updates lists with the given customerId and priority.
        Node* node = new Node();
        node->data = make_pair(customerId, priority);
        Node *prev = head;
        Node *curr = head->next;
        while (curr != NULL)
        {
                // Check whether given customerId is already existed in linked list
                if (curr->data.first == customerId)
                {
                        // if given customerId is already existed then remove entry from the linked list
                        prev->next = curr->next;
                        break;
                }
                prev = curr;
                curr = curr->next;
        }
        prev = head;
        curr = head->next;
        while (curr != NULL)
        {
            //This loop finds the point where new node should be inserted.
                if (curr->data.second < priority)
                {
                        break;
                }
                prev = curr;
                curr = curr->next;
        }
        prev->next = node;
        node->next = curr;

}
int main()
{
        ifstream infile;
        infile.open("priorityqueue.txt");
        Node *head = new Node(); //Dummy head node;
        head->data = make_pair(-1, 5);//Dummy data
        head->next = NULL;
        int customerId, priority;
        while (infile >> customerId >> priority)
        {
                update_list(head, customerId, priority);
        }
        display(head->next);
    //  Asks users for more updates
        cout << "Make another request by entering your customerId and priority\n";
        while (cin >> customerId >> priority)
        {
           // Asks user for more updates
                update_list(head, customerId, priority);
                display(head->next);
                cout << "Make another request by entering your customerId and priority\n";
        }
        return 0;
}