optimize jaccard distance computation and the ranking

[MarahGamdou]

• I run a line_profiler on the ranking function and discovered that the line I modified takes 91.4 of the run time of the rank function. By modifying we can save a lot of ranking time.
• For the Jaccard distance, the code is performing a lot of not-needed computation that is increasing the reranking time.

[L1aoXingyu]

Thank you so much! I will check it later.