/in/foo.cc: In member function 'bigint bigint::operator=(bigint)':
/in/foo.cc:26:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < n.s.size(); i++) s.push_back(n.s[i]);
                         ~~^~~~~~~~~~~~
/in/foo.cc: In member function 'void bigint::scan()':
/in/foo.cc:43:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 1; i < s.size() / 2; i++) {
                             ~~^~~~~~~~~~~~~~
/in/foo.cc:49:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 1; i <= s.size() / 2; i++) {
                             ~~^~~~~~~~~~~~~~~
/in/foo.cc: In member function 'bool bigint::operator<(bigint)':
/in/foo.cc:60:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (len < a.s.size())
             ~~~~^~~~~~~~~~~~
/in/foo.cc:62:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (len > a.s.size())
             ~~~~^~~~~~~~~~~~
/in/foo.cc: In member function 'bool bigint::operator==(bigint)':
/in/foo.cc:73:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (len != a.s.size())
             ~~~~^~~~~~~~~~~~~
/in/foo.cc: In member function 'bool bigint::operator>(bigint)':
/in/foo.cc:82:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (len < a.s.size())
             ~~~~^~~~~~~~~~~~
/in/foo.cc:84:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (len > a.s.size())
             ~~~~^~~~~~~~~~~~
/in/foo.cc: In member function 'bigint bigint::operator/(bigint)':
/in/foo.cc:257:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 1; i < p.s.size(); i++) swap(tmp, p.s[i]);
                             ~~^~~~~~~~~~~~
/in/foo.cc:255:17: warning: unused variable 'i' [-Wunused-variable]
             int i = p.s.size() - 1;
                 ^
/in/foo.cc: In member function 'bigint bigint::operator/=(bigint)':
/in/foo.cc:300:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 1; i < p.s.size(); i++) swap(tmp, p.s[i]);
                             ~~^~~~~~~~~~~~
/in/foo.cc:298:17: warning: unused variable 'i' [-Wunused-variable]
             int i = p.s.size() - 1;
                 ^
/in/foo.cc: In member function 'bigint bigint::operator%(bigint)':
/in/foo.cc:334:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 1; i < p.s.size(); i++) swap(tmp, p.s[i]);
                             ~~^~~~~~~~~~~~
/in/foo.cc:332:17: warning: unused variable 'i' [-Wunused-variable]
             int i = p.s.size() - 1;
                 ^
/in/foo.cc: In member function 'bigint bigint::operator%=(bigint)':
/in/foo.cc:361:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 1; i < p.s.size(); i++) swap(tmp, p.s[i]);
                             ~~^~~~~~~~~~~~
/in/foo.cc:359:17: warning: unused variable 'i' [-Wunused-variable]
             int i = p.s.size() - 1;
                 ^