foo.cc: In function 'void dts::tr_dfs1(dts::ll, dts::ll)':
foo.cc:29:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (ll i=0;i<tr[now].s.size();i++)
                     ~^~~~~~~~~~~~~~~~~
foo.cc: In function 'void dts::tr_dfs2(dts::ll, dts::ll)':
foo.cc:48:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (ll i=0;i<tr[now].s.size();i++)
                         ~^~~~~~~~~~~~~~~~~
foo.cc: In function 'void dts::main()':
foo.cc:161:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld%lld",&n,&q);
         ~~~~~^~~~~~~~~~~~~~~~~~
foo.cc:163:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%lld",&a[i]);
             ~~~~~^~~~~~~~~~~~~~
foo.cc:169:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%lld\n",&fa);
             ~~~~~^~~~~~~~~~~~~~
foo.cc:188:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%c%lld%lld\n",&o,&x,&y);
             ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc: In function 'dts::ll dts::ask(dts::ll, dts::ll)':
foo.cc:149:25: warning: array subscript is below array bounds [-Warray-bounds]
             ians+=st_ask(&nst[-1],1,tr[tr[i].top].id,tr[i].id);
                   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:151:25: warning: array subscript is below array bounds [-Warray-bounds]
             jans+=st_ask(&nst[-1],1,tr[tr[j].top].id,tr[j].id);
                   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:152:33: warning: array subscript is below array bounds [-Warray-bounds]
         ll ansn=ians+jans+st_ask(&nst[-1],1,tr[lcan].id,tr[i].id)+st_ask(&nst[-1],1,tr[lcan].id,tr[j].id)-st_ask(&nst[-1],1,tr[lcan].id,tr[lcan].id);
                           ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:152:73: warning: array subscript is below array bounds [-Warray-bounds]
         ll ansn=ians+jans+st_ask(&nst[-1],1,tr[lcan].id,tr[i].id)+st_ask(&nst[-1],1,tr[lcan].id,tr[j].id)-st_ask(&nst[-1],1,tr[lcan].id,tr[lcan].id);
                                                                   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:152:113: warning: array subscript is below array bounds [-Warray-bounds]
         ll ansn=ians+jans+st_ask(&nst[-1],1,tr[lcan].id,tr[i].id)+st_ask(&nst[-1],1,tr[lcan].id,tr[j].id)-st_ask(&nst[-1],1,tr[lcan].id,tr[lcan].id);
                                                                                                           ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:153:23: warning: array subscript is below array bounds [-Warray-bounds]
         ll ansl=st_ask(&lst[-1],1,tr[lcan].dep,tr[x].dep)+st_ask(&lst[-1],1,tr[lcan].dep,tr[y].dep)-st_ask(&lst[-1],1,tr[lcan].dep,tr[lcan].dep);
                 ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:153:65: warning: array subscript is below array bounds [-Warray-bounds]
         ll ansl=st_ask(&lst[-1],1,tr[lcan].dep,tr[x].dep)+st_ask(&lst[-1],1,tr[lcan].dep,tr[y].dep)-st_ask(&lst[-1],1,tr[lcan].dep,tr[lcan].dep);
                                                           ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:153:107: warning: array subscript is below array bounds [-Warray-bounds]
         ll ansl=st_ask(&lst[-1],1,tr[lcan].dep,tr[x].dep)+st_ask(&lst[-1],1,tr[lcan].dep,tr[y].dep)-st_ask(&lst[-1],1,tr[lcan].dep,tr[lcan].dep);
                                                                                                     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc: In function 'void dts::main()':
foo.cc:181:17: warning: array subscript is below array bounds [-Warray-bounds]
         st_build(&nst[-1],1,1,cnt,&d[0]);
         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:183:17: warning: array subscript is below array bounds [-Warray-bounds]
         st_build(&lst[-1],1,1,maxdep,&d[0]);
         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:194:30: warning: array subscript is below array bounds [-Warray-bounds]
                     st_update(&lst[-1],1,x,x,y);
                     ~~~~~~~~~^~~~~~~~~~~~~~~~~~
foo.cc:196:30: warning: array subscript is below array bounds [-Warray-bounds]
                     st_update(&lst[-1],1,x,x,-y);
                     ~~~~~~~~~^~~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务