Question

Data structures question

Modify the pool data type in the following way: Assume now that every element can appear at most once in the data structure. An insertion must now check for duplicates. Implement the same operations as before, but with duplicate checking. What is the complexity of each operation in the worst case?

Answer 1

Solution: import java.util.*; import java.lang.*i class ModifyMain static boolean checkDuplicatesFunc (int all, int s) // this is for empty hashset Hashset« Integer> hset new HashSet<Integer>(); for (int x-0; x<a.lengthi x++) // If the element is already present in hash, then we found // a duplicate within s if (hset .contains (a [x])) return true; //insert element to hashset hset .add (a[x]) // delete the s+1 if (x -s) hset .remove (a [x-s]) return false;

public static void main (Stringl] args) //array elements int al 10, 15, 13, 14, 13, 25, 36 if (checkDuplicatesFunc (a, 13) ) System.out.println("The element is duplicate"); else system.out.printin("The element is not duplicate") Sample Output: C:Windows system321cmd.exe D:>javac Modif yMain.java D:Njava Modif yMain The element is duplicate Here we keep tracks of the elements using Hashset in the data structure. Using Hashset, we can find check whether given element is already there in the inserted array. Complexity for checkDuplicatesFunc in the above algorithm is O (n)
Copyable Code:

import java.util.*;

import java.lang.*;

class ModifyMain

{

    static boolean checkDuplicatesFunc(int a[], int s)

    {

        // this is for empty hashset

        HashSet<Integer> hset = new HashSet<Integer>();

        for (int x=0; x<a.length; x++)

        {

            // If the element is already present in hash, then we found

            // a duplicate within s

            if (hset .contains(a[x]))

               return true;

            //insert element to hashset

            hset .add(a[x]);

            // delete the s+1

            if (x >= s)

              hset .remove(a[x-s]);

        }

        return false;

    }

     public static void main (String[] args)

    {

        //array elements

        int a[] = {10, 15, 13, 14, 13, 25, 36};

        if (checkDuplicatesFunc(a, 13))

           System.out.println("The element is duplicate");

        else

           System.out.println("The element is not duplicate");

    }

}