/in/foo.cc: In function 'void dfs(std::__cxx11::string)':
/in/foo.cc:47:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(n.size()<maxlen)
     ~~~~~~~~^~~~~~~
/in/foo.cc:48:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<=n.size();i++)//insert
              ~^~~~~~~~~~
/in/foo.cc:55:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i==n.size())ce=n[0];
      ~^~~~~~~~~~
/in/foo.cc:66:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<n.size();i++)//erase
              ~^~~~~~~~~
/in/foo.cc:71:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i==n.size()-1)ce=n[0];
      ~^~~~~~~~~~~~
/in/foo.cc:80:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<n.size();i++)//swap
              ~^~~~~~~~~
/in/foo.cc:81:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<n.size();j++)
               ~^~~~~~~~~