foo.cc: In function 'void Output(std::vector<int>&)':
foo.cc:23:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |         for(int i=0;i<v.size();i++)
      |                     ~^~~~~~~~~
foo.cc: In function 'void OutputEven(std::vector<int>&)':
foo.cc:30:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |         for(int i=0;i<v.size();i++)
      |                     ~^~~~~~~~~

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