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

#define TRUNCATION 1e-10

int main()
{
  int loop, n;
  double x, term, sum;

  printf("       x       exp(-x)       series       terms\n");

  for (loop = 0; loop <= 100; loop += 10)
  {
    x = (double)loop;

    sum = 1.0;
    term = 1;
    n = 1;

    while (fabs(term) > TRUNCATION)
    {
      term *= -x / ((double)n);

      sum += term;
      n++;
    }

    printf("%12f %12g %12g %5d\n", x, exp(-x), sum, n - 1);
  }
}