/in/foo.cc: In member function 'BigInteger BigInteger::operator+(const BigInteger&) const':
/in/foo.cc:76:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (!g&&i>=num.size()&&i>=b.num.size()) break;
                     ~^~~~~~~~~~~~
/in/foo.cc:76:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (!g&&i>=num.size()&&i>=b.num.size()) break;
                                    ~^~~~~~~~~~~~~~
/in/foo.cc:78:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (i<num.size()) x+=num[i];
                 ~^~~~~~~~~~~
/in/foo.cc:79:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (i<b.num.size()) x+=b.num[i];
                 ~^~~~~~~~~~~~~
/in/foo.cc: In member function 'BigInteger BigInteger::operator-(const BigInteger&) const':
/in/foo.cc:98:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (!g&&i>=num.size()&&i>=b.num.size()) break;
                     ~^~~~~~~~~~~~
/in/foo.cc:98:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (!g&&i>=num.size()&&i>=b.num.size()) break;
                                    ~^~~~~~~~~~~~~~
/in/foo.cc:100:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (i<num.size()) x+=num[i];
                 ~^~~~~~~~~~~
/in/foo.cc:101:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             if (i<b.num.size()) x-=b.num[i];
                 ~^~~~~~~~~~~~~
/in/foo.cc: In member function 'BigInteger BigInteger::operator/(const long long int&) const':
/in/foo.cc:133:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i=0;i<num.size();i++) c.num.push_back(0);
                      ~^~~~~~~~~~~
/in/foo.cc: In function 'std::ostream& operator<<(std::ostream&, const BigInteger&)':
/in/foo.cc:202:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int j=0;j<strlen(buf);j++) out<<buf[j];
                          ~^~~~~~~~~~~~
/in/foo.cc: In function 'std::istream& operator>>(std::istream&, BigInteger&)':
/in/foo.cc:213:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i=start;i<len;i++)
                          ~^~~~