how to find the subsequences of an array

void printPowerSet(int *set, int set_size) {
  /*set_size of power set of a set with set_size
    n is (2**n -1)*/
  unsigned int pow_set_size = pow(2, set_size);
  int counter, j;
 
  /*Run from counter 000..0 to 111..1*/
  for(counter = 0; counter < pow_set_size; counter++)
  {
    for(j = 0; j < set_size; j++)
    {
      /* Check if jth bit in the counter is set
         If set then pront jth element from set */
      if(counter & (1<<j))
        printf("%d", set[j]);
    }
    printf("\n");
  }
}
 
/*Driver program to test printPowerSet*/
int main()
{
  int set[] = {1,2,3};
  printPowerSet(set, 3);
 
  getchar();
  return 0;
}