/in/foo.cc: In function 'int mt(int, int)':
/in/foo.cc:14:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int kx=k;kx<(tr[x].size());kx++){
                      ~~^~~~~~~~~~~~~~~
/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:35:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(yc[p][j]==(tr[p].size()) || yc[p][j]==(tr[j].size())) continue;//两者存在包含关系就跳过 
            ~~~~~~~~^~~~~~~~~~~~~~~~
/in/foo.cc:35:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(yc[p][j]==(tr[p].size()) || yc[p][j]==(tr[j].size())) continue;//两者存在包含关系就跳过 
                                        ~~~~~~~~^~~~~~~~~~~~~~~~