#include <iostream>
#include <ctime>  // For time()
#include <cstdlib> // For rand(), srand(), RAND_MAX
using namespace std;

double my_rand( double a = 0.0, double b = 1.0 );

int main()
{
    srand( time(0) );  // or time(NULL)
    
    const int n = 1000;
    int k;
    double x[n];  //  If using a variable to define the array dimension, make it a const
    
    for ( k = 0; k < n; k++ ) {
        x[k] = my_rand();
    }
    
    double sum = 0.0;
    for ( k = 0; k < n; k++ ) {
        sum += x[k];
    }
    
    cout << "The average value is " << sum / n << endl;
    
    cout << "\n\n"; system( "PAUSE" );
    return( 0 );
}

double my_rand( double a, double b )
{
       double x = double ( rand() ) / RAND_MAX;
       return( a + ( b - a ) * x );
}