XOR two binary strings of unequal lengths

Given two binary string of unequal lengths A and B, the task is to print the binary string which is the XOR of A and B.
Examples:

Input: A = “11001”, B = “111111” 
Output: 100110
Input: A = “11111”, B = “0” 
Output: 11111 

Approach: The idea is to first make both the strings of equal length and then perform the XOR of each character one by one and store it in the resultant string.
Below is the implementation of the above approach:  

C++

// C++ implementation of the approach
#include <bits/stdc++.h>
using namespace std;

// Function to insert n 0s in the
// beginning of the given string
void addZeros(string& str, int n)
{
    for (int i = 0; i < n; i++) {
        str = "0" + str;
    }
}

// Function to return the XOR
// of the given strings
string getXOR(string a, string b)
{

    // Lengths of the given strings
    int aLen = a.length();
    int bLen = b.length();

    // Make both the strings of equal lengths
    // by inserting 0s in the beginning
    if (aLen > bLen) {
        addZeros(b, aLen - bLen);
    }
    else if (bLen > aLen) {
        addZeros(a, bLen - aLen);
    }

    // Updated length
    int len = max(aLen, bLen);

    // To store the resultant XOR
    string res = "";
    for (int i = 0; i < len; i++) {
        if (a[i] == b[i])
            res += "0";
        else
            res += "1";
    }

    return res;
}

// Driver code
int main()
{
    string a = "11001", b = "111111";

    cout << getXOR(a, b);

    return 0;
}

Java

// Java implementation of the approach
class GFG
{

    // Function to insert n 0s in the
    // beginning of the given string
    static String addZeros(String str, int n)
    {
        for (int i = 0; i < n; i++)
        {
            str = "0" + str;
        }
        return str;
    }

    // Function to return the XOR
    // of the given strings
    static String getXOR(String a, String b)
    {

        // Lengths of the given strings
        int aLen = a.length();
        int bLen = b.length();

        // Make both the strings of equal lengths
        // by inserting 0s in the beginning
        if (aLen > bLen)
        {
            a = addZeros(b, aLen - bLen);
        }
        else if (bLen > aLen)
        {
            a = addZeros(a, bLen - aLen);
        }

        // Updated length
        int len = Math.max(aLen, bLen);

        // To store the resultant XOR
        String res = "";

        for (int i = 0; i < len; i++)
        {
            if (a.charAt(i) == b.charAt(i))
                res += "0";
            else
                res += "1";
        }
        return res;
    }

    // Driver code
    public static void main (String[] args)
    {
        String a = "11001", b = "111111";

        System.out.println(getXOR(a, b));
    }
}

// This code is contributed by AnkitRai01

Python3

# Python3 implementation of the approach

# Function to insert n 0s in the
# beginning of the given string
def addZeros(strr, n):
    for i in range(n):
        strr = "0" + strr
    return strr

# Function to return the XOR
# of the given strings
def getXOR(a, b):

    # Lengths of the given strings
    aLen = len(a)
    bLen = len(b)

    # Make both the strings of equal lengths
    # by inserting 0s in the beginning
    if (aLen > bLen):
        b = addZeros(b, aLen - bLen)
    elif (bLen > aLen):
        a = addZeros(a, bLen - aLen)

    # Updated length
    lenn = max(aLen, bLen)

    # To store the resultant XOR
    res = ""
    for i in range(lenn):
        if (a[i] == b[i]):
            res += "0"
        else:
            res += "1"

    return res

# Driver code
a = "11001"
b = "111111"

print(getXOR(a, b))

# This code is contributed by Mohit Kumar

C#

// C# implementation of the approach
using System;

class GFG
{

    // Function to insert n 0s in the
    // beginning of the given string
    static String addZeros(String str, int n)
    {
        for (int i = 0; i < n; i++)
        {
            str = "0" + str;
        }
        return str;
    }

    // Function to return the XOR
    // of the given strings
    static String getXOR(String a, String b)
    {

        // Lengths of the given strings
        int aLen = a.Length;
        int bLen = b.Length;

        // Make both the strings of equal lengths
        // by inserting 0s in the beginning
        if (aLen > bLen)
        {
            a = addZeros(b, aLen - bLen);
        }
        else if (bLen > aLen)
        {
            a = addZeros(a, bLen - aLen);
        }

        // Updated length
        int len = Math.Max(aLen, bLen);

        // To store the resultant XOR
        String res = "";

        for (int i = 0; i < len; i++)
        {
            if (a[i] == b[i])
                res += "0";
            else
                res += "1";
        }
        return res;
    }

    // Driver code
    public static void Main(String[] args)
    {
        String a = "11001", b = "111111";

        Console.WriteLine(getXOR(a, b));
    }
}

// This code is contributed by Rajput-Ji

Javascript

<script>
    // Javascript implementation of the approach

    // Function to insert n 0s in the
    // beginning of the given string
    function addZeros(str, n)
    {
        for (let i = 0; i < n; i++)
        {
            str = "0" + str;
        }
        return str;
    }

    // Function to return the XOR
    // of the given strings
    function getXOR(a, b)
    {

        // Lengths of the given strings
        let aLen = a.length;
        let bLen = b.length;

        // Make both the strings of equal lengths
        // by inserting 0s in the beginning
        if (aLen > bLen)
        {
            a = addZeros(b, aLen - bLen);
        }
        else if (bLen > aLen)
        {
            a = addZeros(a, bLen - aLen);
        }

        // Updated length
        let len = Math.max(aLen, bLen);

        // To store the resultant XOR
        let res = "";

        for (let i = 0; i < len; i++)
        {
            if (a[i] == b[i])
                res += "0";
            else
                res += "1";
        }
        return res;
    }

    let a = "11001", b = "111111";

      document.write(getXOR(a, b));

    // This code is contributed by divyeshrabadiya07.
</script>

Output:

100110

Time Complexity: O(len), len=Max(length a,length b)

Auxiliary Space: O(len)