/in/foo.cc: In function 'void print2(int)':
/in/foo.cc:22:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (unsigned int i = 0; i < a; i++)
                            ~~^~~
/in/foo.cc:27:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (i <= (a - 1) / 2)
         ~~^~~~~~~~~~~~~~
/in/foo.cc:33:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      if (i < a - 1)
          ~~^~~~~~~