/in/foo.cc: In function 'void solve()':
/in/foo.cc:22:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for( i=0; i<edge[p].size(); i++ )
             ~^~~~~~~~~~~~~~~
/in/foo.cc:15:8: warning: unused variable 'j' [-Wunused-variable]
  int i,j,s=n;
        ^