Add two numbers without using arithmetic operators

Write a function Add() that returns sum of two integers. The function should not use any of the arithmetic operators (+, ++, –, -, .. etc).

Sum of two bits can be obtained by performing XOR (^) of the two bits. Carry bit can be obtained by performing AND (&) of two bits.
Above is simple Half Adder logic that can be used to add 2 single bits. We can extend this logic for integers. If x and y don’t have set bits at same position(s), then bitwise XOR (^) of x and y gives the sum of x and y. To incorporate common set bits also, bitwise AND (&) is used. Bitwise AND of x and y gives all carry bits. We calculate (x & y) << 1 and add it to x ^ y to get the required result.

C

// C Program to add two numbers
// without using arithmetic operator
#include<stdio.h>

int Add(int x, int y)
{
    // Iterate till there is no carry  
    while (y != 0)
    {
        // carry now contains common 
        //set bits of x and y
        int carry = x & y;  

        // Sum of bits of x and y where at 
        //least one of the bits is not set
        x = x ^ y; 

        // Carry is shifted by one so that adding
        // it to x gives the required sum
        y = carry << 1;
    }
    return x;
}

int main()
{
    printf("%d", Add(15, 32));
    return 0;
}

Java

// Java Program to add two numbers
// without using arithmetic operator
import java.io.*;

class GFG 
{
    static int Add(int x, int y)
    {
        // Iterate till there is no carry
        while (y != 0) 
        {
            // carry now contains common
            // set bits of x and y
            int carry = x & y;

            // Sum of bits of x and 
            // y where at least one 
            // of the bits is not set
            x = x ^ y;

            // Carry is shifted by 
            // one so that adding it 
            // to x gives the required sum
            y = carry << 1;
        }
        return x;
    }
    
    // Driver code
    public static void main(String arg[]) 
    {
        System.out.println(Add(15, 32));
    }
}

// This code is contributed by Anant Agarwal.

Python3

# Python3 Program to add two numbers
# without using arithmetic operator
def Add(x, y):

    # Iterate till there is no carry 
    while (y != 0):
    
        # carry now contains common
        # set bits of x and y
        carry = x & y

        # Sum of bits of x and y where at
        # least one of the bits is not set
        x = x ^ y

        # Carry is shifted by one so that   
        # adding it to x gives the required sum
        y = carry << 1
    
    return x

print(Add(15, 32))

# This code is contributed by
# Smitha Dinesh Semwal

C#

// C# Program to add two numbers
// without using arithmetic operator
using System;

class GFG 
{
    static int Add(int x, int y)
    {
        // Iterate till there is no carry
        while (y != 0) 
        {
            // carry now contains common
            // set bits of x and y
            int carry = x & y;

            // Sum of bits of x and 
            // y where at least one 
            // of the bits is not set
            x = x ^ y;

            // Carry is shifted by 
            // one so that adding it 
            // to x gives the required sum
            y = carry << 1;
        }
        return x;
    }
    
    // Driver code
    public static void Main() 
    {
        Console.WriteLine(Add(15, 32));
    }
}

// This code is contributed by vt_m.

PHP


<?php
// PHP Program to add two numbers
// without using arithmetic operator

function Add( $x, $y)
{
    
    // Iterate till there is
    // no carry 
    while ($y != 0)
    {
        
        // carry now contains common 
        //set bits of x and y
        $carry = $x & $y; 

        // Sum of bits of x and y where at 
        //least one of the bits is not set
        $x = $x ^ $y; 

        // Carry is shifted by one 
        // so that adding it to x 
        // gives the required sum
        $y = $carry << 1;
    }
    return $x;
}

    // Driver Code
    echo Add(15, 32);

// This code is contributed by anuj_67.
?>

Output :

47

Following is the recursive implementation for the same approach.

int Add(int x, int y)
{
    if (y == 0)
        return x;
    else
        return Add( x ^ y, (x & y) << 1);
}

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Improved By : vt_m




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