Lenstra, J.K.

problem algorithm vertex processor time windows window search vertex j departure time machine completion number departure exchange 2- optimality arrival time 2- exchange arrival computer value completion time function vertex i phase lenstra .... space solution salesman problem time window salesman optimality savelsbergh class polynomial vertex k sums algorithm model k-exchange section complexity job completion times 2- exchanges p space departure times condition implementation order variable procedure completion times operation polynomial time n numbers improvement release university functions e ij vertice figure feasibility k edges scheduling science amsterdam lawler computation time-constrained centre search strategy 2 j +1 arrival times aij m.w.p time-constrained tsp travel times release dates problem size operations research 1 downto 0 theory