RR Graph Direct Link Problem

[amin1377]

This function adds the edges that correspond to direct links between blocks. In this line it is assumed that adding the sub_tile_offset to z whould result in the sub_tile index which is used to access to the corresponding sub_tile in this line. However, this assumption is not true. Neither sub_tile_offset nor z have anything to do with the sub_tile index. They are related to the capacity number of the intended sub_tile.

@vaughnbetz