//Reads data and displays a bar graph showing productivity for each plant.
#include <iostream>
#include <cmath>
using namespace std;
const int NUMBER_OF_PLANTS = 4;

void inputData(int a[], int lastPlantNumber);
//Precondition: lastPlantNumber is the declared size of the array a.
//Postcondition: For plantNumber = 1 through lastPlantNumber:
//a[plantNumber-1] equals the total production for plant number plantNumber.

void scale(int a[], int size);
//Precondition: a[0] through a[size-1] each have a nonnegative value.
//Postcondition: a[i] has been changed to the number of 1000s (rounded to
//an integer) that were originally in a[i], for all i such that 0 <= i <= size-1.

void graph(const int asteriskCount[], int lastPlantNumber);
//Precondition: a[0] through a[lastPlantNumber-1] have nonnegative values.
//Postcondition: A bar graph has been displayed saying that plant
//number N has produced a[N-1] 1000s of units, for each N such that
//1 <= N <= lastPlantNumber

void getTotal(int& sum);
//Reads nonnegative integers from the keyboard and
//places their total in sum.

int round(double number);
//Precondition: number >= 0. 
//Returns number rounded to the nearest integer.

void printAsterisks(int n);
//Prints n asterisks to the screen.

int main( )
{
    int production[NUMBER_OF_PLANTS];

    cout << "This program displays a graph showing\n"
         << "production for each plant in the company.\n";

    inputData(production, NUMBER_OF_PLANTS);
    scale(production, NUMBER_OF_PLANTS);
    graph(production, NUMBER_OF_PLANTS);
    return 0;
}

void inputData(int a[], int lastPlantNumber)
{
    for (int plantNumber = 1; 
                   plantNumber <= lastPlantNumber; plantNumber++)
    {
        cout << endl
             << "Enter production data for plant number "
             << plantNumber << endl;
        getTotal(a[plantNumber - 1]);
    }
}

void getTotal(int& sum)
{
    cout << "Enter number of units produced by each department.\n"
         << "Append a negative number to the end of the list.\n";

    sum = 0;
    int next;
    cin >> next;
    while (next >= 0)
    {
        sum = sum + next;
        cin >> next;
    }

    cout << "Total = " << sum << endl;
}

void scale(int a[], int size)
{
    for (int index = 0; index < size; index++)
        a[index] = round(a[index]/1000.0);
}

int round(double number)
{
    return static_cast<int>(floor(number + 0.5));
}

void graph(const int asteriskCount[], int lastPlantNumber)
{
    cout << "\nUnits produced in thousands of units:\n";
    for (int plantNumber = 1; 
                plantNumber <= lastPlantNumber; plantNumber++)
    {
        cout << "Plant #" << plantNumber << " ";
        printAsterisks(asteriskCount[plantNumber - 1]);
        cout << endl;
    }
}

void printAsterisks(int n)
{
    for (int count = 1; count <= n; count++)
        cout << "*";
}