     #nodes  #regions   #procs   #which case
      24        3        7       RegionsSpanProcs
     nodeID   regionID   procID
       0         0         0
       1         0         0
       2         0         0
       3         0         0
       4         0         1
       5         0         1
       6         0         1
       7         0         1
       7         1         2
       8         1         2
       9         1         2
      10         1         2
      11         1         2
      12         1         2
      13         1         2
      14         1         2
      15         1         2
      15         2         3
      16         2         3
      17         2         3
      18         2         3
      19         2         4
      20         2         4
      21         2         5
      22         2         5
      23         2         6
