Travel Trajectory Frequent Pattern Mining Based on Differential Privacy Protection

Algorithm 3

Trajectory weighted graph protection (TWGP).

Input: Trajectory , privacy budget ,Threshold

Output: Frequent

1. Trajectory Graph Database = TGDC ()

2. ifthen

3. return

4. is sorted from smallest to largest by the number of edges of

5.

6. The number of is ;

7. for=1 todo:

8. enumerate and its children is ’s child with one edge growth in /

9. for each do:

10.   ;

11.   ;

12.   if:

13.     ;

14.    end if

15.   end for

16. select a subgraph from such that Pr{Selecting subgraph g} ;

17. ;

18. end for

19. return;