Maximum value of XOR among all triplets of an array

https://www.geeksforgeeks.org/maximum-value-of-xor-among-all-triplets-of-an-array/

Given an array of integers ‘arr’, the task is to find the maximum XOR value of any triplet pair among all the possible triplet pairs.
Note: An array element can be used more than once.

Examples:

Input: arr[] = {3, 4, 5, 6}
Output: 7
The triplet with maximum XOR value is {4, 5, 6}.

• Store all possible values of XOR between all possible two-element pairs from the array in a set.
• Set data structure is used to avoid the repetitions of XOR values.
• Now, XOR between every set element and array element to get the maximum value for any triplet pair.

    // function to count maximum

    // XOR value for a triplet

    static void Maximum_xor_Triplet(int n, int a[])

    {

        // set is used to avoid repetitions

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

  

        for (int i = 0; i < n; i++)

        {

            for (int j = i; j < n; j++)

            {

  

                // store all possible unique

                // XOR value of pairs

                s.add(a[i] ^ a[j]);

            }

        }

  

        int ans = 0;

        for (Integer i : s) 

        {

            for (int j = 0; j < n; j++)

            {

  

                // store maximum value

                ans = Math.max(ans, i ^ a[j]);

            }

        }

        System.out.println(ans);

    }