question: private void dagDFS ( Lop root , boolean [ ] marked ) { if ( ! IDMap . containsKey ( root . getID ( ) ) ) return ; int mapID = IDMap . get ( root . getID ( ) ) ; if ( marked [ mapID ] ) return ; marked [ mapID ] = true ; for ( Lop lop : root . getOutputs ( ) ) { dagDFS ( lop , marked ) ; } }
target:  Method to perform depth-first traversal from a given node in the DAG. Store the reachability information in marked[] boolean array.