#include <stdio.h>
#include <stdlib.h>
#include <math.h>
/* generate a random value weighted within the normal (gaussian) distribution */
static double gauss(void)
{
  double x = (double)random() / RAND_MAX,
         y = (double)random() / RAND_MAX,
         z = sqrt(-2 * log(x)) * cos(2 * M_PI * y);
  return z;
}
/* aggregate 100k cycles and display */
main(void) {
  static long g[11], i = 0;
  srandom(time(NULL));
  while (i++ < 100000)
    g[(long)floor(gauss()+0.5) + 5]++;
  for (i = 0; i < 11; i++)
    printf("%2ld: %ld\n", i, g[i]);
  return 0;
}