foo.cc: In function 'void Output(std::vector<int>&)':
foo.cc:10:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |         for(int i=0; i<v.size(); i++)
      |                      ~^~~~~~~~~
foo.cc: In function 'void Output(std::vector<bool>&)':
foo.cc:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |         for(int i=0; i<v.size(); i++)
      |                      ~^~~~~~~~~
foo.cc: In function 'int Sum(std::vector<int>&, std::vector<bool>&)':
foo.cc:25:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |         for(int i=0; i<a.size(); i++)
      |                      ~^~~~~~~~~
foo.cc: In function 'void dfs(std::vector<int>&, int, std::vector<bool>&, int)':
foo.cc:36:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |         if(ith==a.size())
      |            ~~~^~~~~~~~~~

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