// FILE: ShowDiff.cpp
// COMPUTES THE AVERAGE VALUE OF AN ARRAY OF DATA AND PRINTS
//    THE DIFFERENCE BETWEEN EACH VALUE AND THE AVERAGE

#include <iostream.h>
#include <iomanip.h>
#include "apvector.h"

int main()
{
   // Local data ...
   const int num_items = 8;

   apvector <double> x(num_items);	// array of data
   int i;						// loop control variable
   double average;				// average value of data
   double sum;					// sum of the data

   // Enter the data.
   cout << "Enter " << x.length() << " numbers: ";
   for (i = 0; i < x.length(); i++)
      cin >> x[i];

   // Compute the average value.
   sum = 0.0;					// initialize sum
   for (i = 0; i < x.length(); i++)
      sum += x[i];					// add each element to sum
   average = sum / x.length();			// get average value

   // Set i/o flags and precision for output to ensure 1 decimal
   //    place for output.
   cout.setf (ios::fixed);
   cout.precision (1);
   cout << "The average value is " << average << endl << endl;

   // Display the difference between each item and the average.
   cout << "Table of differences between x[i] and the average." << endl;
   cout << setw (4) << "i" << setw (8) << "x[i]"
        << setw (14) << "difference" << endl;
   for (i = 0; i < x.length(); i++)
      cout << setw (4) << i << setw (8) << x[i] 
          << setw (14) << (x[i] - average) << endl;
   return 0;
}