My program seems to work correctly on all tests I tried, including all the tests that could be found in topics of this problem's discussion. Nevertheless, I always have WA #1 when I submit it as a solution, so I guess something is wrong not with the algorithm, but with I/O code. Here it is (I know that the rules of the board deny posting code, but this is only input/output code, no part of algorithm is exposed):

int main(int argc, char **argv){
  int n;
  std::cin >> n;

  Labyrinth lab(n);

  for(int i = 0; i < n; i++){
    std::string s;
    std::getline(std::cin, s);
    // strip the last linebreak, if any
    if(s[s.length() - 1] == '\n') s.resize(s.length() - 1);
    // if the string is empty
    // (for example,  after reading the
    // number from the first line),
    // reread it (modifying the current line index)
    if(s.length() == 0) { i--; continue; }
    for(int j = 0; j < n; j++){
      if(s[j] == '#') lab.add_wall_block(j, i);
    }
  }
  std::cout << 9 * lab.total_walls_visible() << std::endl;
  return 0;
}

(if the formatting is broken, here is the alternative: http://itpaste.ru/92461 )

Edited by author 01.10.2010 13:49