foo.cc: In member function ‘void Map::Del(int)’:
foo.cc:67:35: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   67 |                 for (int j = i; j < x.size() - 1; j++)
      |                                 ~~^~~~~~~~~~~~~~
foo.cc: In member function ‘bool Map::search(int, int)’:
foo.cc:75:35: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   75 |                 for (int i = 0; i < x.size(); i++)
      |                                 ~~^~~~~~~~~~