Pfthb

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class FreqItemset 

 // method to read parameters of file ( bucket and min sup)
 public int no_of_baskets_and_minsup(BufferedReader br) throws IOException 
 String line1 = br.readLine();
 return new int Integer.parseInt(line1.split(" ")[0]), Integer.parseInt(line1.split(" ")[1]);
 

 public void pass1(String file) 

 try 
 BufferedReader inputbr = new BufferedReader(new FileReader(file));
 int res = no_of_baskets_and_minsup(inputbr);
 int baskets = res[0];
 int minsup = res[1];
 System.out.println("Number of bukcets:"+baskets);
 System.out.println("Min support is:"+minsup);

 //pass 1 logic
 String basket=null;
 int unique_items = new int[100];
 while( (basket = inputbr.readLine()) !=null ) // for each basket

 String temp = basket.split(",");
 for(int i =1; i<temp.length; i++) // for each item in basket

 unique_items[Integer.parseInt(temp[i])]++; // increment counts
 

 //todo create hashtable maintaing bukcet and count

 //For each pair of items in a basket.. 
 // hash the pair to a bukce;
 // add 1 to the count of that bukcet;
 
 catch (Exception ex) 
 System.out.println("Something wrong in Phase 1 :" + ex.getMessage() + "nn" + ex.getStackTrace());

 
 

 public static void main(String args) 

 String filename = "input.txt";
 long t1= System.currentTimeMillis();
 FreqItemset obj = new FreqItemset();
 obj.pass1(filename);
 long t2= System.currentTimeMillis();
 System.out.println("Time mili "+(t2-t1));
 

In implementing the PCY algorithm with Multihash technique for Frquent itemset mining .. in the pass 1 i need have created an array of 1-itemsets and their counts. Now i need to consider each pair from each basket and hash it to bucket using a hash function. I have to create 2 has tables in Pass 1 ( multihash PCY).

I am unable to figure a way : given a pair i,j of items how shoud i implement hash-table using my own has function like eg. (i*j)%51 and other similar one for second hash-table.

I read alot about hashing hashtables but didnt find a way out .