#include <stdio.h>
#include <math.h>
#include <stdlib.h>

#define NATOM 100000
int main()
{
  int i, j, k;
  double ddsum, dx, dy, dz, dxA, dyA, dzA, dxB, dyB, dzB;
  double* dsum;

  dsum = (double*)malloc(NATOM*sizeof(double));
  system("date");
  for (i = 0; i < NATOM; i++) {
    dsum[i] = 0.0;
  }
  for (i = 0; i < NATOM; i++) {
    for (j = 0; j < NATOM; j++) {
      dx = j*5.0;
      dy = j*6.0 - 7.0;
      dz = j*2.0 + 3.0;
      dsum[i] += dx*dx + dy*dy + dz*dz;
    }
  }
  ddsum = 0.0;
  for (i = 0; i < NATOM; i++) {
    ddsum += dsum[i];
  }
  printf("DDsum = %16.8e\n", ddsum);
  system("date");
  for (i = 0; i < NATOM; i++) {
    dsum[i] = 0.0;
  }
  for (i = 0; i < NATOM; i++) {
    for (j = 0; j < NATOM-1; j += 2) {
      dxA = j*5.0;
      dyA = j*6.0 - 7.0;
      dzA = j*2.0 + 3.0;
      dxB = (j+1)*5.0;
      dyB = (j+1)*6.0 - 7.0;
      dzB = (j+1)*2.0 + 3.0;
      dsum[i] += dxA*dxA + dyA*dyA + dzA*dzA + dxB*dxB + dyB*dyB + dzB*dzB;
    }
    if (j != NATOM) {
      dxA = j*5.0;
      dyA = j*6.0 - 7.0;
      dzA = j*2.0 + 3.0;
      dsum[i] += dxA*dxA + dyA*dyA + dzA*dzA;
    }
  }
  ddsum = 0.0;
  for (i = 0; i < NATOM; i++) {
    ddsum += dsum[i];
  }
  printf("DDsum = %16.8e\n", ddsum);
  system("date");
}