Travel Trajectory Frequent Pattern Mining Based on Differential Privacy Protection

Algorithm 1

Trajectory graph database construction.

Input: Trajectory database ,

Output: Trajectory Graph Database

1. for each in: / Summarize all trajectory data by traversing the starting points in /

2. 

3. if not in :

4. 

5. for each in:

6. 

7. for each in:

8.   if:

9.     

10. end for

11. /For each trajectory, points and edges are added to the trajectory graph to construct a complete graph structure /

12. for each in:

13. for j in range ():

14.  ifnot in:

15.    

16.    ifnot in:

17.     

18.     Edge (,).w+=1 Add edge weight to the graph /

19.  end for

20. 

21. end for

22. return