C++ Program to Print uncommon elements from two sorted arrays

Given two sorted arrays of distinct elements, we need to print those elements from both arrays that are not common. The output should be printed in sorted order. 
Examples :

Input : arr1[] = {10, 20, 30}
        arr2[] = {20, 25, 30, 40, 50}
Output : 10 25 40 50
We do not print 20 and 30 as these
elements are present in both arrays.

Input : arr1[] = {10, 20, 30}
        arr2[] = {40, 50}
Output : 10 20 30 40 50
        

The idea is based on merge process of merge sort. We traverse both arrays and skip common elements.

C++

// C++ program to find uncommon elements of
// two sorted arrays
#include <bits/stdc++.h>
using namespace std;

void printUncommon(int arr1[], int arr2[],
                           int n1, int n2)
{

    int i = 0, j = 0, k = 0;
    while (i < n1 && j < n2) {

        // If not common, print smaller
        if (arr1[i] < arr2[j]) {
            cout << arr1[i] << " ";
            i++;
            k++;
        }
        else if (arr2[j] < arr1[i]) {
            cout << arr2[j] << " ";
            k++;
            j++;
        }

        // Skip common element
        else {
            i++;
            j++;
        }
    }

    // printing remaining elements
    while (i < n1) {
        cout << arr1[i] << " ";
        i++;
        k++;
    }
    while (j < n2) {
        cout << arr2[j] << " ";
        j++;
        k++;
    }
}

// Driver code
int main()
{
    int arr1[] = {10, 20, 30};
    int arr2[] = {20, 25, 30, 40, 50};

    int n1 = sizeof(arr1) / sizeof(arr1[0]);
    int n2 = sizeof(arr2) / sizeof(arr2[0]);

    printUncommon(arr1, arr2, n1, n2);

    return 0;
}

Output :

10 25 40 50

Time Complexity: O(n1 + n2), where n1 and n2 represents the size of the given two arrays.
Auxiliary Space: O(1), no extra space is required, so it is a constant.

Please refer complete article on Print uncommon elements from two sorted arrays for more details!