/** ***************************************************************************
 * @remark compute an arithmetic serices in two ways                          * 
 *     from largest term to smallest, and                                     *
 *     from smallest term to largest                                          *
 *                                                                            *
 * @author Henry M. Walker                                                    *
 * @file  arithmetic series.c                                                 *
 * @date  August 14, 2022                                                     *
 *                                                                            *
 * @remark Reference                                                          *
 * @remark Consequences of Data Representation on Programming                 *
  https://blue.cs.sonoma.edu/~hwalker/courses/415-sonoma.sp23/readings/data-rep-consequences.html
 *                                                                            *
 *****************************************************************************/

#include <stdio.h>

int main ( ) {
  int n = 0;
  double term = 100000.0;
  double oldSum = 0.0;
  double sum =  oldSum + term;
  printf ("adding largest to smallest terms\n");
  while (oldSum != sum) {
    printf ("n: %3d; oldSum:%27.16lf; term:%27.16lf sum:  %27.16lf \n",
            n, oldSum, term, sum);
    n++;
    oldSum = sum;
    term /= 10.0;
    sum = oldSum + term;
  }
  printf ("adding the last term %27.16lf, ", term);
  printf ("the loop finished in %d iterations with sum =  %27.16lf\n\n",
          n, sum);

  // start with last term utilezed in previous computation
  int i;
  int numTerms = n;
  oldSum = 0.0;
  sum =  oldSum + term; 
  printf ("adding from smallest to largest terms\n");
  for (i = 0; i < n; i++) {
    printf ("i: %3d; oldSum:%27.16lf; term:%27.16lf sum:  %27.16lf \n",
            i, oldSum, term, sum);
    oldSum = sum;
    term *= 10.0;
    sum = oldSum + term;
  }

  printf ("adding the last term %27.16lf, ", term);
  printf ("loop finished in %d iterations with sum =  %27.16lf\n\n",
          i, sum);

  return 0;
}