| Input: Group-Skyline R, Directed Skyline graph (DSG), The number of result k |
| Output: top-k Group-Skyline groups(S) |
| 1 C ← SLGS(R) |
| 2 number(i) ← {0} |
| 3 for each pido |
| 4 number(i) ← the number of pi’s children |
| 5 for each CiC do |
| 6 for each group GiCi do |
| 7 use number[] to compute VC for Gi |
| 8 use quick sort to sort the group in Ci |
| 9 S ← select k Group-Skyline groups from C |
| 10 returnS |
