/in/foo.cc: In function 'int main()':
/in/foo.cc:21:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<ba.size();i+=2)
              ~^~~~~~~~~~
/in/foo.cc:24:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<bb.size();i+=2)
              ~^~~~~~~~~~
/in/foo.cc: In function 'void ZXL(std::vector<int>, int, std::vector<int>&, std::vector<int>&)':
/in/foo.cc:41:6: warning: variable 'b' set but not used [-Wunused-but-set-variable]
  int b=0,cnt=1;
      ^