Page 211 - 《软件学报》2020年第11期

3526 Journal of Software 软件学报 Vol.31, No.11, November 2020

输出:查询结果集 R.
1. if VTs(Q)<PLs max or VTe(Q)>PLe max then
2. R=∅; goto Step 44;
3. end if
4. PLs mid =the midpoint of PLs, PLe mid =the midpoint of PLe; mid=Int((max+mid)/2);
5. if VTs(Q)<PLs mid and VTe(Q)>PLe mid then
6. if max<min then
7. min=mid–1; goto Step 4;
8. else goto Step 44;
9. end if
10. else if VTs(Q)≥PLs mid and VTe(Q)≤PLe mid then
11. if max<min then
12. max=mid+1; goto Step 4;
13. else goto Step 44;
14. end if
15. else if VTs(Q)<PLs mid and VTe(Q)≤PLe mid then
16. min=mid–1; goto Step 20;
17. else if VTs(Q)≥PLs mid and VTe(Q)>PLe mid then
18. min=mid–1; goto Step 32;
19. end if
20. PLs mid =the midpoint of PLs;

21. if VTs(Q)<PLs mid then
22. if max<min then
23. min=mid–1; goto Step 4;
24. else goto Step 20;
25. end if
26. else if VTs(Q)≥PLs mid then
27. if max<min then
28. max=mid+1; goto Step 4;
29. else goto Step 20;
30. end if
31. end if
32. PLe mid =the midpoint of PLe;
33. if VTe(Q)>PLe mid then
34. if max<min then
35. min=mid–1; goto Step 15;
36. else goto Step 20;
37. end if
38. else if VTe(Q)≤PLe mid then
39. if max<min then
40. max=mid+1; goto Step 15;
41. else goto Step 20;