说明：  Mining sequential pattern is one of the common data mining task for many real-life applications.Previous existing algorithm such as CAMLS(Constraint-based Apriori Algorithm for Mining Long Sequences) mines the complete set of frequent sequences(Long) satisfying a min-sup threshold in a sequence.However,mining long sequences will generate an explosive number of frequent sequences, which is prohibitively costly in both run time and space storage.In this paper, we propose to improve CAMLS algorithm to produce only for closed sequences.Instead of mining full set of sequences,we plan to mine only short(closed) sequences.i.e.,those containing,no super sequences with same support.Ou