Question

Given

P={p_1, p_2, ..., p_m}, the set of products available at a local grocery store;

D={T_1, T_2, ..., T_N}, the set of transactions that were completed at this store in the past year, where each T_i (i in [1,N]) is a subset of P;

min_freq, a user-specified parameter (e.g., 5%).

A product is said to be frequent if it occurs in at least min_freq of the transactions in D. By the same token, a pair of products is said to be frequent if it occurs in at least min_freq of the transactions in D. Also, it's straightforward to prove the following claim: if a product is not frequent, none of the pairs that involve this product will be frequent. Use this claim to design an algorithm to find all the frequent products and frequent product pairs in D.

Represent your algorithm in pseudo code.

Answer 1

Step 1: Count quantity of things Present in each transaction and place in an arrary a[]. Step 2: Find transactions having most items i.e maximum items within array a[]. step 3: If count (max (a[]) ? min then transfer those transactions to an another array arr[] [], else find subset. step 4: Compare energy transaction in arr[] with alterative transactions. step 5: Take a counter 'c' and increase country if we have a tendency to found similar item sets in arr [] []. step 6: if { c ? min] then item set is said to be most frequency item set. step 7: If { c < min_val] then find subsets of all transactions and store in array sub [] []. step 8: Now, max = max - 1 step 9: Add transactions of sub [] [] to arr [] []. step 10: Repeat from step 3 until frequent item set found.