/in/foo.cc: In function 'int main()':
/in/foo.cc:27:109: warning: 'max_rear_flag' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if (max_head_flag == n - max_rear_flag || max_head_flag + 1 == n - max_rear_flag - 1 || max_head_flag == 0 || max_rear_flag == n-1)
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~