foo.cc: In member function 'int SeqList::Find(int)':
foo.cc:20:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |   for (int i = 0; i < a.size(); i++)
      |                   ~~^~~~~~~~~~
foo.cc: In member function 'void SeqList::Delete(int)':
foo.cc:27:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |   for (int i = k; i < a.size() - 1; i++)
      |                   ~~^~~~~~~~~~~~~~
foo.cc: In member function 'SeqList SeqList::Common(SeqList&)':
foo.cc:57:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |   for (int i = 0; i < a.size(); i++)
      |                   ~~^~~~~~~~~~
foo.cc:58:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |    for (int j = 0; j < L.a.size(); j++)
      |                    ~~^~~~~~~~~~~~

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