foo.cc: In function ‘void BubbleSort(std::vector<Complex>&)’:
foo.cc:58:27: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<Complex>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   58 |         for (int i = 0; i < nums.size() - 1; i++)
      |                         ~~^~~~~~~~~~~~~~~~~
foo.cc:60:37: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<Complex>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   60 |                 for (int j = i+1; j < nums.size() - i - 1; j++)
      |                                   ~~^~~~~~~~~~~~~~~~~~~~~