/in/foo.cc: In member function 'void BigIntArray::Output()':
/in/foo.cc:32:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < v.size() - 1; i++)
                         ~~^~~~~~~~~~~~~~
/in/foo.cc:34:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int j = 0; j < v.size() - 1 - i; j++)
                             ~~^~~~~~~~~~~~~~~~~~
/in/foo.cc:40:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                     for (int k = 0; j < v[j].size(); k++)
                                     ~~^~~~~~~~~~~~~
/in/foo.cc:55:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < v.size(); i++)
                         ~~^~~~~~~~~~
/in/foo.cc:57:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int j = 0; j < v[i].size(); j++)
                             ~~^~~~~~~~~~~~~