/in/foo.cc: In function 'void dts::tr_dfs1(dts::ll, dts::ll)':
/in/foo.cc:32:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (ll i=0;i<tr[now].s.size();i++)
               ~^~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'void dts::tr_dfs2(dts::ll, dts::ll)':
/in/foo.cc:53:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (ll i=0;i<tr[now].s.size();i++)
                ~^~~~~~~~~~~~~~~~~
/in/foo.cc: In member function 'void dts::segtree::update(dts::ll&, dts::ll, dts::ll, dts::ll, dts::ll)':
/in/foo.cc:101:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (now==-1||now+1>st.size())
                  ~~~~~^~~~~~~~~~
/in/foo.cc: In member function 'dts::ll dts::segtree::ask(dts::ll, dts::ll, dts::ll)':
/in/foo.cc:140:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (now==-1||now+1>st.size())
                  ~~~~~^~~~~~~~~~