/in/foo.cc: In function 'void tarjan(int, int)':
/in/foo.cc:94:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<arr[id].kids.size();i++) {
                 ~^~~~~~~~~~~~~~~~~~~~
/in/foo.cc:99:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<qarr[id].conn.size();i++) {
                 ~^~~~~~~~~~~~~~~~~~~~~