#include <iostream.h>
#include <math.h>
#include <conio.h>


void pause () {

  cout << "\nHit any key to continue....\n";
  getch ();

}


struct point {
  double z, y;
};


struct rectangle {
  double z_size, y_size;
  double area;
  point centre;
};


double square (double x) {
  return x * x;
}


double cube (double x) {
  return x * x * x;
}


// function "calculate_moments" goes in here


int main () {

  const int max_rectangles = 40;
  rectangle rectangles[max_rectangles];
  double Iz, Iy, Iyz;
  int n = 0; // number of rectangles
  point centroid;

  for (;;) {

    cout << "\nEnter z and y size of rectangle (0, 0 to quit): ";
    cin >> rectangles[n].z_size >>  rectangles[n].y_size;

    if ((rectangles[n].z_size <= 0) ||
        (rectangles[n].y_size <= 0)) {
      break;
    }

    // compute area
    rectangles[n].area = rectangles[n].z_size * rectangles[n].y_size;

    cout << "Enter z and y co-ordinates of rectangle centre: ";
    cin >> rectangles[n].centre.z >>  rectangles[n].centre.y;
;
    if (++n == max_rectangles) {
      cout << "\n** Max nember of rectangles reached. **\n";
      break;
    }

  }

  // do the calculations
  calculate_moments (rectangles, n, centroid, Iz, Iy, Iyz);

  // output the results
  cout << "\nCentroid z = " << centroid.z
       << " Centroid y = " << centroid.y << endl
       << "\nIz = " << Iz << " Iy = " << Iy << " Iyz = " << Iyz << endl;


  pause ();
  return 0;

}