#include <stdio.h>
#include <string.h>

int main(int argc,char **argv) 
{
	char input[100];
  unsigned int  nr_subst, nr_elem; 

	printf("Give your input:"); scanf("%s", input);
	nr_elem = strlen(input);
	printf("Input has %d `elements", nr_elem);
  /* 2^nr_elem-1 */
	nr_subst = 2 << (nr_elem - 1); 
	
	for(int i = 0; i < nr_subst; i++)	{
			printf("Subset number %d :: ", i);
			for(int j = 0; j < nr_elem; j++) {
						/* is jth bit set in i */
						if ( i & (1 << j) ) 
								printf("%c",	input[j]);
			}
			printf("\n");
	}
						
	return 0;
}