/*  Christopher D'Urso
 *  chris@durso.org
 *  for more information see 
 *  http://www.durso.org/PerfectShuffling/Perfect_Shuffling.html
 *
 *  June 7, 2002
 *  updated: 8/21/04
 *  Compute the period of perfect suffles for a series of sets of objects
 *  NOTE: This program will never end in "real time" UINT64*UINT64 is far
 *  to big a number! so just run as long as you wish or until your storage
 *  runs out!
 */


#include <stdio.h>
#include <assert.h>
#include <stdint.h>

int  main(void){
  FILE*f;
  unsigned long long v;  // position of element 1
  unsigned long long n;  // number of elements in set minus 1
   
  f = fopen("./shuffles.bin_unsignedlonglong", "w");
  assert(f);
  
  for(n = 3; n < (UINT64_MAX/2LL - 1) ; n += 2){
    unsigned long long count = 0;
    v = 1;
    do{
      v = v*2LL % n ;
      count++;
    }while(1 != v);    
    /* 
    *  completed one shuffling at position 1 again
    *  print the results
    */
    fwrite(&count, sizeof(count), 1, f);
  }
  fclose(f);
  return 1;
}