Por favor, resuelva / responda los problemas para que el programa funcione. No entiendo completamente las variables de paso por referencia o valor y creo que eso es lo que hace que esto sea tan difícil. Entonces, si pudieras arreglar el programa. He estado en esto durante los últimos 2 días. He incluido mi código completo.

Paxdiablo sugirió esto y estoy tratando de hacer lo que dijeron

"Una cosa que debe hacer es inicializar totalsqrtfeet a cero en su función principal. Esto se debe a que solo está agregando el tamaño de cada habitación y comienza con un valor aleatorio: junk + a + b + c + d es todavía basura :-)

Además de eso, llama a getUserData desde su función principal y luego nuevamente desde doEstimate. Y luego los vuelves a llamar a los dos en showReport. Por eso pregunta cuatro veces. Simplemente llame a getUserData una vez. Como es tarea, te dejaré que averigües dónde, pero aquí hay una pista. Si lo hace en main (nudge, nudge, wink, wink), también tendrá que pasar las variables a doEstimate, no crear nuevas variables del mismo nombre dentro de esa función y mágicamente esperar que el compilador las asocie con originales "

Cuando ingreso datos de prueba de 1 habitación, 110 pies cuadrados, 15.00. Obtengo el número correcto para las habitaciones en la función de informe pero 0 para todo lo demás

 #include <iostream>
#include <cstdlib>
#include <cmath>
#include <iomanip>

using namespace std;

// Function prototypes
void showMenu();
void getUserData(int &, int &, double &);
void doEstimate(int &, int &, double &, int &, double &, int &, double &, double &);
void showReport(int &, int &, double &, int &, double &, int &, double &, double &);

int main()
{
    int choice = 0;
    int calcGallonsOfPaint = 0, rooms = 0, totalsqrtfeet = 0;
    double calcCostOfPaint = 0, costOfPaint = 0;
    int calcHoursOfLabor = 0;
    double calcLaborCost = 0;
    double calcPaintJobCost = 0;

   // Set up numeric output formatting.
   cout << fixed << showpoint << setprecision(2);

   do
   {
      // Display the menu and get the user's choice.
      showMenu();
      cin >> choice;

      // Validate the menu selection.
      while (choice < 1 || choice > 2)
      {
         cout << "Please enter 1 or 2: ";
         cin >> choice;
      }

      if (choice == 1)
      {

        //User enters information
        getUserData(rooms, totalsqrtfeet, costOfPaint);

        //Information from getUserData is used to make calculations
        doEstimate(rooms, totalsqrtfeet, costOfPaint, calcGallonsOfPaint, calcCostOfPaint, calcHoursOfLabor, calcLaborCost, calcPaintJobCost);

        //Report is generated from user input and calculations
        showReport(rooms, totalsqrtfeet, costOfPaint, calcGallonsOfPaint, calcCostOfPaint, calcHoursOfLabor, calcLaborCost, calcPaintJobCost);

       }
   } while (choice != 2);
   return 0;
}

//*****************************************************************
// Definition of function showMenu which displays the menu.       *
//*****************************************************************

void showMenu()
{
   cout << "\n\t\tPaint Job Estimator Menu\n\n";
   cout << "1. Get Paint Job Estimate\n";
   cout << "2. Quit the Program\n\n";
   cout << "Enter your choice: ";
}

/*
After the paint job estimate is displayed, the menu should be displayed again. 
The number of rooms must be at least 1, the price of the paint per gallon must be at least $15.00, 
and the area for the wall space of each room must be greater than 10 square feet. 
All input validation must be performed with a loop.
*/

void getUserData(int &rooms, int &totalsqrtfeet, double &costOfPaint)
{
    int sqrtfeet;
    int count = 0;

    cout << "Please enter the number of rooms to be painted: ";
    cin >> rooms;

    cout << "Please enter square feet of wall space in room 1: ";
    cin >> sqrtfeet;

    for (count = 2; count <= rooms; count++)
        {   
            cout << "Please eneter square feet of wall space in room " << count << ": ";
            cin >> sqrtfeet;
            totalsqrtfeet += sqrtfeet;
        }   

    cout << "What is the cost of the paint: ";
    cin >> costOfPaint;
}

void doEstimate(int &rooms, int &totalsqrtfeet, double &costOfPaint, int &calcGallonsOfPaint, double &calcCostOfPaint, int &calcHoursOfLabor, double &calcLaborCost, double &calcPaintJobCost)
{


    calcGallonsOfPaint = 1 * (totalsqrtfeet/110);           //Calculates the number of whole gallons of paint required.

    calcCostOfPaint = calcGallonsOfPaint  * costOfPaint;    //Calculates the cost of the paint required.

    calcHoursOfLabor = calcGallonsOfPaint * 6;              //Calculates the number of whole hours of labor required.

    calcLaborCost = calcHoursOfLabor * 15.00;               //Calculates the labor charges.

    //Calculates the cost of the paint job. This is the sum of the labor charges and the cost of the paint required.
    calcPaintJobCost = calcLaborCost + calcCostOfPaint;     


}

void showReport(int &rooms, int &totalsqrtfeet, double &costOfPaint, int &calcGallonsOfPaint, double &calcCostOfPaint, int &calcHoursOfLabor, double &calcLaborCost, double &calcPaintJobCost)
{


    cout << "The number of rooms to be painted: " << rooms << endl;
    cout << "The number of whole gallons of paint required: " << calcGallonsOfPaint << endl;
    cout << "The hours of labor required: " << calcHoursOfLabor << endl;
    cout << "The cost of the paint: " << calcCostOfPaint << endl;
    cout << "The labor charges: " << calcLaborCost << endl;
    cout << "The total cost of the paint job: " << calcPaintJobCost << endl;

    system("pause");
    system("cls");
}