foo.cc: In function 'void change(int, int)':
foo.cc:14:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |   for(int i=0;i<out.size();i++)
      |               ~^~~~~~~~~~~
foo.cc:29:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |  for(int i=0;i<out.size();i++)
      |              ~^~~~~~~~~~~

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