/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:26:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<connections[u].size(); ++i)
                  ~^~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:55:13: error: expected ';' before '{' token
             {
             ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:75:28: error: invalid type argument of unary '*' (have 'int')
     memset(dfn,0,(int)*(N+1));
                            ^
/in/foo.cc:76:28: error: invalid type argument of unary '*' (have 'int')
     memset(low,0,(int)*(N+1));
                            ^