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.

Implementation:

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;
}

Java

// Java program to find uncommon elements
// of two sorted arrays
import java.io.*;

class GFG {

    static 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]) {
                System.out.print(arr1[i] + " ");
                i++;
                k++;
            }
            else if (arr2[j] < arr1[i]) {
                System.out.print(arr2[j] + " ");
                k++;
                j++;
            }

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

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

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

        int n1 = arr1.length;
        int n2 = arr2.length;

        printUncommon(arr1, arr2, n1, n2);
    }
}

// This code is contributed by vt_m

Python3

# Python 3 program to find uncommon
# elements of two sorted arrays


def printUncommon(arr1, arr2, n1, n2) :

    i = 0
    j = 0
    k = 0
    while (i < n1 and j < n2) :

        # If not common, print smaller
        if (arr1[i] < arr2[j]) :
            print( arr1[i] , end= " ")
            i = i + 1
            k = k + 1

        elif (arr2[j] < arr1[i]) :
            print( arr2[j] , end= " ")
            k = k + 1
            j = j + 1

        # Skip common element
        else :
            i = i + 1
            j = j + 1

    # printing remaining elements
    while (i < n1) :
        print( arr1[i] , end= " ")
        i = i + 1
        k = k + 1

    while (j < n2) :
        print( arr2[j] , end= " ")
        j = j + 1
        k = k + 1


# Driver code
arr1 = [10, 20, 30]
arr2 = [20, 25, 30, 40, 50]

n1 = len(arr1)
n2 = len(arr2)

printUncommon(arr1, arr2, n1, n2)



# This code is contributed
# by Nikita Tiwari.

C#

// C# program to find uncommon elements
// of two sorted arrays
using System;
class GFG {

static 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])
            {
                Console.Write(arr1[i] + " ");
                i++;
                k++;
            }
            else if (arr2[j] < arr1[i])
            {
                Console.Write(arr2[j] + " ");
                k++;
                j++;
            }

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

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

    // Driver Code
    public static void Main()
    {
        int []arr1 = {10, 20, 30};
        int []arr2 = {20, 25, 30, 40, 50};

        int n1 = arr1.Length;
        int n2 = arr2.Length;

        printUncommon(arr1, arr2, n1, n2);
    }
}

// This code is contributed by Sam007

PHP

<?php
// PHP program to find uncommon
// elements of two sorted arrays

function printUncommon($arr1, $arr2,
                       $n1, $n2)
{
    $i = 0;
    $j = 0;
    $k = 0;
    while ($i < $n1 && $j < $n2)
    {

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

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

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

// Driver code
$arr1 = array(10, 20, 30);
$arr2 = array(20, 25, 30, 40, 50);

$n1 = sizeof($arr1) ;
$n2 = sizeof($arr2) ;

printUncommon($arr1, $arr2, $n1, $n2);

// This code is contributed by Anuj_67
?>

Javascript

<script>
// JavaScript program to find uncommon elements
// of two sorted arrays

    function printUncommon(arr1,
                     arr2, n1, n2)
    {

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

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

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

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

// Driver Code
        let arr1 = [ 10, 20, 30 ];
        let arr2 = [ 20, 25, 30, 40, 50 ];

        let n1 = arr1.length;
        let n2 = arr2.length;

        printUncommon(arr1, arr2, n1, n2);

// This code is contributed by susmitakundugoaldanga.
</script>

Output :

10 25 40 50

Time Complexity : O(n1 + n2) 
Auxiliary Space : O(1)