Seeking algorithm to invert (reverse? mirror? turn inside-out) a DAG

Question

I\'m looking for an algorithm to \"invert\" (reverse? turn inside-out?) a DAG:

       A*      # I can\'t ascii-art the arrows, so just
      / \\      # pretend          


        

Answer 1

Just do a depth-first search marking where you have already been, and each time you traverse an arrow you add the reverse to your result DAG. Add the leaves as roots.