RIVER ROUTING WITH A GENERALIZED-MODEL

Traditional restrictions on river routing confine the connecting wires to the channel between the terminal rows. In (J. Comput. System Sci. 28 (1984), 420-438) these restrictions were somewhat relaxed, thereby permitting a limited type of routing outside of the channel. Here, the constraints are further relaxed to allow for a new class of ''general ized'' river routings. We show that this new class of generalized rive r routings contains routings that are significantly more compact than those previously considered. in addition, we give a fast polynomial ti me algorithm for producing optimal routings in this new class. The run time of our algorithm is the best possible and is identical to the ti me required to produce optimal river routings under the traditional mo del. (C) 1996 Academic Press, Inc.