/* PROBLEM 2 - C Solution */
/* Hamming distance problem */
#include <stdio.h>
#define MAXBITS 10

void display_string( bit_string, n)
int bit_string[]; int n;
{
    int count;

    for( count=0; count<n; count++ )
	printf("%1d", bit_string[count]);

    printf("\n");
}

void make_copy( string1, n, string2 )
int string1[]; int n; int string2[];
{
    int count;

    for( count=0; count<n; count++ )
	string2[count] = string1[count];
}

void template( bit_string, n, h, nbits )
int bit_string[]; int n; int h; int nbits;
{
    int count;
    int temp_string[MAXBITS];

    if ( h == 0 )
    {
	for( count=0; count<n; count++ )
	    bit_string[count] = 0;
	display_string( bit_string, nbits );
    }
    else
    {
	if ( h == n )
	{
	    for( count=0; count<n; count++ )
		bit_string[count] = 1;
	    display_string(bit_string, nbits );
	}
	else
	{
	    make_copy( bit_string, n, temp_string );
	    bit_string[ n-1 ] = 0;
	    template( bit_string, n-1, h, nbits );
	    make_copy( temp_string, n, bit_string );
	    bit_string[ n-1 ] = 1;
	    template( bit_string, n-1, h-1, nbits );
	}
    }
}

main()
{
    int bit_string[MAXBITS];
    int n;
    int h;

    printf("%s \n", "NumberBits, HamDist?");
    scanf("%d %d", &n, &h);
    printf("\n");
    template(bit_string, n, h, n );
}