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

/*Integer x be converted to binary format. 
 *Return binary array instance of x. 
 *-1 act as array terminator.
 */
int*
toBin(int x) {
  
  int *ret, c = 0, i, j; 

  ret = malloc(sizeof *ret * 32); 
  
  /*Shift bits to left one by one until x is zero.*/
  /*Store each bit to array*/
  while (x > 0) {
    if ( (x & 1) == 1)
      ret[c] = 1; 
    else
      ret[c] = 0;
    x >>= 1; c++;
  }
  
  /*Reverse array swapping values*/
  for (j = 0;j < c;j++) {
    for (i = 0;(i+1) < (c-j);i++) {
      ret[i] ^= ret[i+1];
      ret[i+1] ^= ret[i];
      ret[i] ^= ret[i+1];
    }
  }

  ret[c] = -1; //TODO better array terminator

  return ret;
}


int 
main (void) {
  
  int i, c = 0, *arr;   
  
  for (i = 1;i <= 170;i++) {
    arr = toBin(i);
    printf("%d = ", i);
    while (arr[c] != -1) {
      printf("%d",arr[c]);
      c++;      
    }
    c = 0;
    printf("\n");
    free(arr);
  }
  
  return EXIT_SUCCESS;
}