Two-dimensional online bin packing with rotation

In two-dimensional bin packing problems, the input items are rectangles which need to be packed in a non-overlapping manner. The goal is to assign the items into unit squares using an axis-parallel packing. Most previous work on online packing concentrated on items of fixed orientation, which must be assigned such that their bottom side is parallel to the bottom of the bin. In this paper we study the case of rotatable items, which can be rotated by ninety degrees. We give almost tight bounds on the (asymptotic) competitive ratio of bounded space bin packing of rotatable items, and introduce a new unbounded space algorithm. This improves the results of Fujita and Hada.