Question

In this question you have to write a complete function. in C++

MyMedia Publishers uses two parallel arrays to keep track of the number of subscriptions for each of their
50 publications.   
Array  publications holds 1)  the names of the  magazines and newspapers  published
and  array  subscriptions 2)holds  the  number  of  subscriptions  for  each  corresponding  magazine  or
newspaper.
You  have  to write  a  void function, called  findMostSubs to  determine  which  publication
has  the  most  subscribers.

Function findMostSubs has to return the name of the publication as well as
the number of subscribers to that publication.
Assume the following:
• a declaration of a global constant:
const int NUM_PUBS = 50; //number of publications
• four declaration statements in the main function:
string publications[NUM_PUBS]; // titles of the publications
int subscriptions[NUM_PUBS]; // number of subscriptions for the
// corresponding publications
int nrMostSubscriptions; // number of subscriptions for
// publication with most subscriptions
string mostSubscriptions; // title of publication with most
// subscriptions
• values have been assigned already to all the elements of the arrays
• the function is called in the main program as follows:

findMostSubs(publications, subscriptions,
mostSubscriptions, nrMostSubscriptions);

Answer 1

//I changed contsnt number NUM_PUBS to 5 and tested with 5 data in the file, You can change this to 50 and test with 50 publications and subscriptions

#include <iostream>
#include<string>
#include<fstream>
using namespace std;

//function declarations
void findMostSubs(string publications[], int subscriptions[],
   string &mostSubscriptions, int &nrMostSubscriptions);
//a declaration of a global constant:
const int NUM_PUBS = 5; //number of publications //change this number to 50 when you have 50 publications and 50 subscription data in file, to test I changed this to 5 as I have 5 data
int main() {

   //four declaration statements in the main function:
   string publications[NUM_PUBS]; // titles of the publications
   int subscriptions[NUM_PUBS]; // number of subscriptions for the
                               // corresponding publications
   int nrMostSubscriptions; // number of subscriptions for
                           // publication with most subscriptions
   string mostSubscriptions; // title of publication with most
                           //assign some values to publications, as well subscriptions,read from file
   ifstream in1("publications.txt");
   ifstream in2("subscriptions.txt");
   //check if files can be open
   if (!in1 || !in2)
   {
       cout << "Not able to open either or both of the input files, please check" << endl;
       return -1;
   }
   int count = 0;
   //read info into two paralle arrays
   while (!in1.eof())
   {
       getline(in1, publications[count++]);
   }
   count = 0;
   while (!in2.eof())
   {
       in2 >> subscriptions[count++];
   }
   // subscriptions
   //• values have been assigned already to all the elements of the arrays
   //• the function is called in the main program as follows:

   findMostSubs(publications, subscriptions,
       mostSubscriptions, nrMostSubscriptions);
   cout << mostSubscriptions << " publication has " << nrMostSubscriptions << " subscriptions"<<endl;
}

//function definition
void findMostSubs(string publications[], int subscriptions[],
   string &mostSubscriptions, int &nrMostSubscriptions)
{
   nrMostSubscriptions = subscriptions[0];
   for (int i = 0; i<NUM_PUBS; i++)
   {
       if (nrMostSubscriptions < subscriptions[i])
       {
           mostSubscriptions = publications[i];
           nrMostSubscriptions = subscriptions[i];
       }

   }
}

/*Input files with 5 data
publications.txt
Impartial Reporter
Unterrified Democrat
E S Holmans, London
The Arran Banner
Chad Gething, London
scubscriptions.txt
20
10
17
20
28
//tested with 5 data in each file , you can change constant variable declared NUM_PUBS to 50 when testing with large data
Output
Chad Gething, London publication has 28 subscriptions
*/