/in/foo.cc: In function 'void check_vertex()':
/in/foo.cc:55:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int i=1;i<cut_point.size();i++)
                     ~^~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'void tarjan(int)':
/in/foo.cc:75:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i <adj[u].size() ; ++i) {
                     ~~^~~~~~~~~~~~~~
/in/foo.cc: In function 'void bl()':
/in/foo.cc:104:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int j = 0; j <adj[i].size() ; ++j) {
                             ~~^~~~~~~~~~~~~~
/in/foo.cc: In function 'void dfs(int, int, int, int)':
/in/foo.cc:119:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j = 0; j <adj[now].size() ; ++j) {
                         ~~^~~~~~~~~~~~~~~~