foo.cc: In member function 'int SeqList::Search1(int)':
foo.cc:16:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |                 for (int i = 0; i < seq.size(); i++)
      |                                 ~~^~~~~~~~~~~~
foo.cc: In member function 'int SeqList::Search2(int)':
foo.cc:24:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |                 for (int i = 0; i < seq.size(); i++)
      |                                 ~~^~~~~~~~~~~~
foo.cc: In member function 'void SeqList::SearchRemove(int)':
foo.cc:42:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |                 for (int i = k + 1; i <= seq.size(); i++)
      |                                     ~~^~~~~~~~~~~~~
foo.cc: In member function 'std::vector<int> SeqList::Union(SeqList&)':
foo.cc:52:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |                 for (int i = 0; i < seq.size(); i++)
      |                                 ~~^~~~~~~~~~~~
foo.cc:55:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |                 for (int i = 0; i < obj.seq.size(); i++)
      |                                 ~~^~~~~~~~~~~~~~~~
foo.cc:55:17: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   55 |                 for (int i = 0; i < obj.seq.size(); i++)
      |                 ^~~
foo.cc:58:25: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   58 |                         for (int i = 0; i < obj.seq.size(); i++)
      |                         ^~~
foo.cc:58:43: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |                         for (int i = 0; i < obj.seq.size(); i++)
      |                                         ~~^~~~~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:81:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   81 |         for (int i = 0; i < res.size(); i++)
      |                         ~~^~~~~~~~~~~~
foo.cc: In member function 'int SeqList::Search2(int)':
foo.cc:29:9: warning: control reaches end of non-void function [-Wreturn-type]
   29 |         }
      |         ^