foo.cc:76:2: error: expected ‘;’ after struct definition
   76 | }
      |  ^
      |  ;
foo.cc: In member function ‘std::vector<PolyTerm> PolyTerm::mergePolynomials(const std::vector<PolyTerm>&, const std::vector<PolyTerm>&)’:
foo.cc:18:14: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<PolyTerm>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   18 |     while (i < poly1.size() && j < poly2.size())
      |            ~~^~~~~~~~~~~~~~
foo.cc:18:34: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<PolyTerm>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   18 |     while (i < poly1.size() && j < poly2.size())
      |                                ~~^~~~~~~~~~~~~~
foo.cc:25:16: error: expected ‘;’ before ‘；j’
   25 |             i++；j++;
      |                ^~~
foo.cc:41:14: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<PolyTerm>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   41 |     while (i < poly1.size())
      |            ~~^~~~~~~~~~~~~~
foo.cc:46:14: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<PolyTerm>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   46 |     while (j < poly2.size())
      |            ~~^~~~~~~~~~~~~~