Question

Fix the following program (C++).

#include <iostream>
#include <cmath>
#include <vector>
#include <limits>
using namespace std;


/*
 * Calculate the square of a number
 */
float square (float x)
{
        return x*x;
}

/*
 * Calculate the average from a list of floating point numbers
 */
float average(vector<float>& values)
{
        float sum = 0.0f;
        float average;

        for (float x : values)
                sum += x;
        average = sum / values.size();
        return average;
}

/**
 Calculate the standard deviation from a vector of floats
 1) Calculate the sum of the squares of the differences between dataSet[i]
    and the mean using the square function.
 2)Divide this result, diffSquared, by (values.size() - 1)
 3)Take the square root of the result
 **/
float stddeviation(vector<float>& values)
{
        float diffSquared = 0.0f;
        float stdDev;

        /*Do a sum of the squares of the differences over the range of
        vector values*/
        for (float x : values)
        {
                diffSquared += square(x - average(values));
        }
        diffSquared /= values.size() - 1;
        stdDev = sqrt(diffSquared);

        return stdDev;
}

/*
 * Main
 */
int main()
{
        int valueCount; //number of vector values


/////////////////////User input: get number of values and the actual values/////////////////////////////////////
        /*
         * Prompt the user and get the number of values to enter
         */

        cout << "Please enter the amount of values to be entered >";

        vector<float> dataSet(valueCount); // initialize the vector with the given data size
        //Get user input values. Error check for non-numbers.
        //Run the for loop for the size of the vector dataSet to avoid out-of-bounds errors
        for (vector<double>::size_type i = 0; i < valueCount; i++)
        {
                cout << "Please enter the values, one at a time > ";

                //Check for valid input, loop until valid
                while ( !(cin >> dataSet[i]) )
                {
                        cin.clear(); //clear input
                        cin.ignore(numeric_limits<streamsize>::max(), '\n');
                        cerr << "Input Error: non-numeric input. Please enter only numbers.";
                }
        }
///////////////////////////////End Value Input/////////////////////////////////////////////////////////////////

////////////////////////////////////////////////Computations///////////////////////////////////////////////
        /*
         * Calculate and display the average of the data using function average()
         */
        cout << "\nThe average of the entered values is " << average(dataSet) << ".";

        /*
         * Calculate and display the standard deviation of the data using stddeviation()
         */
        cout << "\nThe standard deviation of the data is " << stddeviation(dataSet) << ".\n";

        return(0);
}