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

int main(int argc, char **argv) {
  int key[6][6] = {
    {0, 1, 0, 1, 0, 1},
    {0, 0, 0, 0, 1, 0},
    {0, 0, 1, 0, 0, 0},
    {0, 1, 0, 0, 1, 0},
    {0, 0, 0, 0, 0, 1},
    {0, 0, 0, 1, 0, 0}
  };

  int perm[36];

  int i, j, k;
  k = 0;

  FILE *infile;
  FILE *outfile;
  char in[36];
  char out[36];

  for (i=0; i<6; i++)
    for (j=0; j<6; j++)
      if (key[i][j] == 1)
        perm[k++] = 6*i+j;
  for (j=0; j<6; j++)
    for (i=5; i>=0; i--)
      if (key[i][j] == 1)
        perm[k++] = 6*j+(5-i);
  for (i=5; i>=0; i--)
    for (j=5; j>=0; j--)
      if (key[i][j] == 1)
        perm[k++] = 6*(5-i)+(5-j);
  for (j=5; j>=0; j--)
    for (i=0; i<6; i++)
      if (key[i][j] == 1)
        perm[k++] = 6*(5-j)+i;

 
    if(argc != 3)
    {
        fprintf(stderr, "Usage: %s input_file output_file\n", argv[0]);
        return 1;
    }
 
    if((infile = fopen(argv[1], "rb")) == NULL)
    {
        fprintf(stderr, "Error: cannot open %s\n", argv[1]);
        return 1;
    }
 
    else if((outfile = fopen(argv[2], "wb")) == NULL)
    {
        fprintf(stderr, "Error: cannot open %s\n", argv[2]);
        return 1;
    }


    int n;
    char array[36000];
    char *parray = array;

    while(!feof(infile))
    {
        n = fread(in, 1, 36, infile);
        if (n != 36) {
          printf("error : n=%d\n", n);
          break;
        }
        int i;
        for (i=0; i<36; i++)
          out[i] = in[perm[i]];
        parray = strncpy(parray, out, 36);
        parray += 36;
    }

    char *p = array;
    n = 0;
    while (*p++ == '#')
      n++;
    printf("nb de # : %d\n", n);
    *(p-1) = '\0';
    while (*--parray != '\0')
        fwrite(parray, 1, 1, outfile);

    fclose(infile);
    fclose(outfile);
 
    return 0;
}