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

void print_gray(unsigned char * massiv, unsigned int size)
{
     for (int i=(size-1); i>=0; --i)
          printf("%d",massiv[i]);
};

void generate_gray(unsigned int n,unsigned int k)
{
  unsigned char * gray_digit = (unsigned char *) malloc(sizeof(unsigned char)*k);
  int i,p,j;
  memset(gray_digit,0,sizeof(unsigned char)*k);
  i = 0;
  do
  {
     print_gray(gray_digit,k);
     printf(" - :%d\n", i);
     ++i;
     if(i>n)
        break;
     p=0;
     j=i;
     while ( j%2 == 0)
      {
         j = j/2;
         ++p;
      };
      if (p < k)
       gray_digit[p] = 1 - gray_digit[p];
   }while( p < k );
   
  free(gray_digit);  
};



int main()
{
    unsigned int k,n;
    
    printf("Input k (bits length):");
    scanf("%d",&k);
    printf("Input n (num iteration):");
    scanf("%d",&n);
    
    generate_gray(n,k);
    
    return 0;
}