Dropping method for rectangle packing problem

In the rectangle packing problem, encoding schemes to represent the placements of rectangles are the key factors determining the efficiency of algorithms. SEQ-PAIR is one of the most sophisticated encoding scheme, which has been considered to have a small solution space. In this paper, we begin with a packing procedure that does not look so smart. This procedure, however, leads us to another encoding scheme DS (the abbreviation for Dropping Schedule) whose solution space has the same size as that of SEQ-PAIR. Moreover, we introduce encoding scheme LOT as an advanced version of DS, which has a smaller solution space