Find the two non-repeating elements in an array of repeating elements

repeated.java

/* Given an array in which all numbers except two are repeated once. (i.e. we have 2n+2 numbers and n numbers are occurring twice and remaining two have occurred once). Find those two numbers in the most efficient way */
class RepeatElement
{
    void printRepeating(int arr[], int size) 
    {
        int xor = arr[0];
        int set_bit_no;
        
        int i;
        int x = 0, y = 0;

        for (i = 1; i < size; i++)
            xor ^= arr[i];

        /* Get the rightmost set bit in set_bit_no */
        set_bit_no = (xor & ~(xor - 1));
        
        System.out.println("Set Bit " + set_bit_no);
        
        for (i = 0; i < size; i++) {
            
            int a = arr[i] & set_bit_no;
            
            System.out.println( " arr[i] = " + arr[i] );
            System.out.println( " a = " + a );
            
            if (a != 0)
                x = x ^ arr[i]; /*XOR of first set in arr[] */
            else
                y = y ^ arr[i]; /*XOR of second set in arr[] */
        }
        
        System.out.println("The two reppeated elements are :");
        System.out.println(x + " " + y);
    }

    public static void main(String[] args) 
    {
        RepeatElement repeat = new RepeatElement();
        int arr[] = {2, 3, 7, 9, 11, 2, 3, 11};
        int arr_size = arr.length;
        repeat.printRepeating(arr, arr_size);
    }
}