Find lost element from a duplicated array

import java.util.Arrays;

public class GFG {
    // Function to find the missing element between two arrays
    // n1 and n2 are the sizes of arr1 and arr2 respectively
    static int findMissing(int[] arr1, int[] arr2, int n1, int n2) {
        int i, j;
        boolean found;
        for (i = 0; i < n1; i++) {
            found = false;

            // Check if the element from arr1 exists in arr2
            for (j = 0; j < n2; j++) {
                if (arr1[i] == arr2[j]) {
                    found = true; // Set found to true if the element is found in arr2
                    break; // Exit the loop since we found a match
                }
            }

            // If the element is not found in arr2, it is the missing element
            if (!found) {
                return arr1[i]; // Return the missing element
            }
        }

        // If no missing element is found, return -1
        return -1;
    }

    public static void main(String[] args) {
        int[] arr1 = {1, 4, 5, 7, 9};
        int[] arr2 = {4, 5, 7, 9};
        int n1 = arr1.length; // Get the size of arr1
        int n2 = arr2.length; // Get the size of arr2

        // Find the missing element between arr1 and arr2
        int missing = findMissing(arr1, arr2, n1, n2);

        // Output the result
        if (missing == -1) {
            System.out.println("No missing element");
        } else {
            System.out.println(missing);
        }
    }
}

// Java program to find missing element
// from same arrays
// (except one missing element)

import java.io.*;
class MissingNumber {

    /* Function to find missing element based
     on binary search approach. arr1[] is of
     larger size and N is size of it.arr1[] and 
     arr2[] are assumed to be in same order. */
    int findMissingUtil(int arr1[], int arr2[],
                        int N)
    {
        // special case, for only element
        // which is missing in second array
        if (N == 1)
            return arr1[0];

        // special case, for first
        // element missing
        if (arr1[0] != arr2[0])
            return arr1[0];

        // Initialize current corner points
        int lo = 0, hi = N - 1;

        // loop until lo < hi
        while (lo < hi) {
            int mid = (lo + hi) / 2;

            // If element at mid indices are
            // equal then go to right subarray
            if (arr1[mid] == arr2[mid])
                lo = mid;
            else
                hi = mid;

            // if lo, hi becomes 
            // contiguous, break
            if (lo == hi - 1)
                break;
        }

        // missing element will be at hi 
        // index of bigger array
        return arr1[hi];
    }

    // This function mainly does basic error
    // checking and calls findMissingUtil
    void findMissing(int arr1[], int arr2[], 
                              int M, int N)
    {
        if (N == M - 1)
        System.out.println("Missing Element is "
        + findMissingUtil(arr1, arr2, M) + "\n");
        else if (M == N - 1)
        System.out.println("Missing Element is "
        + findMissingUtil(arr2, arr1, N) + "\n");
        else
        System.out.println("Invalid Input");
    }

    // Driver Code
    public static void main(String args[])
    {
        MissingNumber obj = new MissingNumber();
        int arr1[] = { 1, 4, 5, 7, 9 };
        int arr2[] = { 4, 5, 7, 9 };
        int M = arr1.length;
        int N = arr2.length;
        obj.findMissing(arr1, arr2, M, N);
    }
}

// This code is contributed by Anshika Goyal.

// Java program to find missing element
// from one array such that it has all 
// elements of other array except one.
// Elements in two arrays can be in any order.

import java.io.*;
class Missing {
    
    // This function mainly does XOR of 
    // all elements of arr1[] and arr2[]
    void findMissing(int arr1[], int arr2[], 
                              int M, int N)
    {
        if (M != N - 1 && N != M - 1) {
        System.out.println("Invalid Input");
            return;
        }

        // Do XOR of all element
        int res = 0;
        for (int i = 0; i < M; i++)
            res = res ^ arr1[i];
        for (int i = 0; i < N; i++)
            res = res ^ arr2[i];

        System.out.println("Missing element is "
                                          + res);
    }

    // Driver Code
    public static void main(String args[])
    {
        Missing obj = new Missing();
        int arr1[] = { 4, 1, 5, 9, 7 };
        int arr2[] = { 7, 5, 9, 4 };
        int M = arr1.length;
        int N = arr2.length;
        obj.findMissing(arr1, arr2, M, N);
    }
}

// This code is contributed by Anshika Goyal.