// Program to take the sum of the members of a structure to another array
#include <stdio.h>
#include <time.h>

struct Vector {
  double *a, *b, *c, *d, *e, *f, *g, *h;
};

int main()
{
  int i, k, n;
  Vector vec;
  double *r;
  printf("Array size    Elapsed time [sec] \n");

  for (int k=1; k<=20; k++) {
    // Array size
    int n = k * 2000000;

    // Allocation
    r = new double[n];
    vec.a = new double[n]; vec.b = new double[n];
    vec.c = new double[n]; vec.d = new double[n];
    vec.e = new double[n]; vec.f = new double[n];
    vec.g = new double[n]; vec.h = new double[n];

    // Initialization
    for (i=0; i<n; i++) {
      vec.a[i] = 1.0;
      vec.b[i] = 1.0;
      vec.c[i] = 1.0;
      vec.d[i] = 1.0;
      vec.e[i] = 1.0;
      vec.f[i] = 1.0;
      vec.g[i] = 1.0;
      vec.h[i] = 1.0;
    }

    // Start time
    clock_t time0 = clock();

    // Main calculation: find the sum of all members of vec
    for (i=0; i<n; i++)
      r[i] = vec.a[i] + vec.b[i] + vec.c[i] + vec.d[i]
	+ vec.e[i] + vec.f[i] + vec.g[i] + vec.h[i];

    // Finish time
    clock_t time1 = clock();

    // Output time
    double time = (double)(time1-time0)/CLOCKS_PER_SEC;
    printf("%11d %15.7f\n",n, time);

    // Deallocation
    delete[] r;
    delete[] vec.a; delete[] vec.b;
    delete[] vec.c; delete[] vec.d;
    delete[] vec.e; delete[] vec.f;
    delete[] vec.g; delete[] vec.h;
  }
  return 0;
}