Let c be a candidate itemset in Ck generated by the Apriori algorithm. How many length-(k - 1) subsets do we need to check in the prune step? Per your previous answer, can you give an improved version of procedure has infrequent subset in Figure 6.4?
![445_8f1e3df0-8e09-4de1-976c-d60999c6d845.png](https://secure.tutorsglobe.com/CMSImages/445_8f1e3df0-8e09-4de1-976c-d60999c6d845.png)