/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:15:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<lj[x].size();i++) if (dfn[lj[x][i]])
               ~^~~~~~~~~~~~~
/in/foo.cc: In function 'void sol(int)':
/in/foo.cc:41:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (i=0;i<lj[x].size();i++)
            ~^~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:77:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (i=0;i<lj[x].size();i++) if (!huan[lj[x][i]]) dl[++wei]=lj[x][i];
            ~^~~~~~~~~~~~~
/in/foo.cc:92:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i=0;i<lt.size();i++) sol(lt[i]);
           ~^~~~~~~~~~
/in/foo.cc:93:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i=0;i<lt.size();i++) for (j=m;j+1;j--) for (k=0;k<=j;k++) bdp[j]=max(bdp[j],bdp[k]+fdp[lt[i]][j-k]);
           ~^~~~~~~~~~