Compilare: user.cpp: In member function ‘void InputReader::next_char()’: user.cpp:19:50: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, sizeof(char), BUFF_SIZE, fin); ^ user.cpp: In function ‘int main()’: user.cpp:80:47: warning: iteration 6u invokes undefined behavior [-Waggressive-loop-optimizations] double dst = 0.0, a = xp + mv * dirx[d], b = yp + mv * diry[d]; ^ user.cpp:79:7: note: containing loop for (int d = 0; d < 8; ++d) { ^ user.cpp:88:48: warning: ‘dir’ may be used uninitialized in this function [-Wmaybe-uninitialized] xp += mv * dirx[dir]; yp += mv * diry[dir]; ^