Solver for puzzle found in showcase at Tekniska Museet.

gistfile1.c

/* https://twitter.com/albertveli/status/356432567106408449/photo/1 */

#include <stdio.h>

void print_rot(char *str, int rot)
{
   char c;

   while (*str) {
      c = *str;
      if (c >= 'A' && c <= 'Z') {
         /* Rotate A-Z */
         printf("%c", ((c - 'A' + rot) % 26) + 'A');
      } else {
         /* Output the rest without modification */
         printf("%c", c);
      }
      str++;
   }

   printf("\n");
}


int main(void)
{
   char *str = "\"NYY TYäQWR HGNA RTRA Eå FRANCFFVYY V EBGZBF äE RAQNFG XBAFGYNQ TYäQWR\". FNQRF NI ERNYVFGRA GBEFGRA NEAR RUERAZNEX V NAQREFGBECRG. PVGNGRG XBZ GERINAQR SEåA RYVN V AVNA.";
   int i;

   /* Output all combinations, only 26 so the correct one is easy to spot. */
   for (i = 0; i < 26; i++) {
      print_rot(str, i);
   }

   return 0;
}


/**
 * Local Variables:
 * mode: c
 * indent-tabs-mode: nil
 * c-basic-offset: 3
 * End:
 */