/in/foo.cc: In function 'void dts::tr_dfs1(int, int)':
/in/foo.cc:35:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |         for (int i=0;i<tr[now].s.size();i++)
      |                      ~^~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'void dts::tr_dfs2(int, int)':
/in/foo.cc:54:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |             for (int i=0;i<tr[now].s.size();i++)
      |                          ~^~~~~~~~~~~~~~~~~