/in/foo.cc: In function 'void clear_all()':
/in/foo.cc:26:54: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
     for(int i=0;i<=ctt;i++){clear(v[i]);lf[i]=line[i]=siz[i]=0;}
                                               ~~~~~~~^~~~~~~~~
/in/foo.cc: In function 'void dfs1(int)':
/in/foo.cc:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<v[x].size();i++)
                 ~^~~~~~~~~~~~