/in/foo.cc: In function 'void Output(std::vector<int>&)':
/in/foo.cc:6:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<v.size(); i++)
               ~^~~~~~~~~
/in/foo.cc: In function 'void QuickSort(int, int, std::vector<int>&)':
/in/foo.cc:14:29: warning: unused variable 'temp' [-Wunused-variable]
  int i=left, j=right, base, temp;
                             ^~~~