/* Last edited on 2007-08-15 21:26:55 by stolfi */

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

int main(int argc, char **argv)
{
  double Mhi = 8.0; /* 2^3 */
  double Mmd = 1024.0 * 1024.0 * 1024.0 * 1024.0 * 32.0; /* 2^45 */
  double Mlo = 1024.0 * 1024.0 * 1024.0 * 1024.0 * 256.0; /* 2^48 */
  int i;
  
  int clo[8];  /* Histogram of bits {0..2} (from low end). */
  int cmd[8];  /* Histogram of bits {3..5}. */
  int chi[8];  /* Histogram of bits {49..51}. */
  
  /* Clear histograms: */
  int k;
  for (k = 0; k < 8; k++) { clo[k] = cmd[k] = chi[k] = 0; }
  
  /* Collect histograms: */
  for (i=0; i < 8000000; i++)
    { double x = drand48();
      int hi = (int)(floor(x*Mhi)) % 8;
      int md = (int)(floor(x*Mmd)) % 8;
      int lo = (int)(floor(x*Mlo)) % 8;
      if (i < 100) { printf("%02d %02d %02d\n", hi, md, lo); }
      clo[lo]++; cmd[md]++; chi[hi]++;
    }
    
  /* Print histograms: */
  for (k = 0; k < 8; k++) 
    { printf("%02d %8d %8d %8d\n", k, chi[k], cmd[k], clo[k]); }
    
  return 0;
}