Removing operation of empty rooms on sequence-pair

In order to specify wiring channels on a given module placement, a method to obtain a floorplan using sequence-pair from a module placement was recently proposed. In the method, empty rooms which are redundant but are generated to keep topology between modules are removed locally on a floorplan. However, this operation is hard to implement because of many operations on a planar graph. In this paper, we reveal underlying theorems in the removing operation of empty rooms, and propose this removing operation not via floorplan but only on sequence-pair