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Code Bit Logic

Swap two numbers using bitwise operator

The problem at hand is to swap two numbers a and b without using a temporary variable, utilizing bitwise operators. Bitwise operators manipulate individual bits in a binary representation of numbers.

Problem Statement:

Given two integers a and b, we need to swap their values using bitwise operators.

Explanation with Suitable Example:

Let's take a simple example to understand the concept of swapping using bitwise operators. Consider a = 5 and b = 9.

  1. Binary Representation:

    a = 0101
    b = 1001

Standard Pseudocode:

1. Let 'a' and 'b' be the two numbers to be swapped.

2. Perform the following steps:
    a. a = a XOR b
    b. b = a XOR b
    c. a = a XOR b

3. The values of 'a' and 'b' have been swapped.

Algorithm Explanation:

  1. First, initialize two variables a and b with the given numbers (e.g., a = 10 and b = 20).

  2. Print the initial values of a and b.

  3. Perform the swap operation using bitwise XOR:

    • a = a ^ b: The bitwise XOR operation between a and b stores the result in a.
    • b = a ^ b: Now, b is updated with the value of a, which means b holds the initial value of a.
    • a = a ^ b: Finally, a is updated with the value of b, which means a now holds the initial value of b.
  4. Print the values of a and b after the swap.

Code Solution

Here given code implementation process.

// C Program
// Swap two numbers using bitwise operator
#include <stdio.h>

int main(int argc, char const *argv[])
{
	// Number
	int a = 10;
	int b = 20;
	printf("\n Before Swap  a : %d  b : %d", a, b);
	// Perform swap operation
	a = a ^ b;
	b = a ^ b;
	a = a ^ b;
	// After swaps
	printf("\n After Swap   a : %d  b : %d", a, b);
	return 0;
}

Output

 Before Swap  a : 10  b : 20
 After Swap   a : 20  b : 10
/*
  Java program
  Swap two numbers using bitwise operator
*/
public class Swapping
{
	public static void main(String[] args)
	{
		// Number
		int a = 10;
		int b = 20;
		System.out.print("\n Before Swap a : " + a + " b : " + b);
		// Perform swap operation
		a = a ^ b;
		b = a ^ b;
		a = a ^ b;
		// After swaps
		System.out.print("\n  After Swap a : " + a + " b : " + b);
	}
}

Output

 Before Swap a : 10 b : 20
  After Swap a : 20 b : 10
// Include header file
#include <iostream>

using namespace std;
/*
  C++ program
  Swap two numbers using bitwise operator
*/
int main()
{
	// Number
	int a = 10;
	int b = 20;
	cout << "\n Before Swap a : " << a << " b : " << b;
	// Perform swap operation
	a = a ^ b;
	b = a ^ b;
	a = a ^ b;
	// After swaps
	cout << "\n  After Swap a : " << a << " b : " << b;
	return 0;
}

Output

 Before Swap a : 10 b : 20
  After Swap a : 20 b : 10
// Include namespace system
using System;
/*
  C# program
  Swap two numbers using bitwise operator
*/
public class Swapping
{
	public static void Main(String[] args)
	{
		// Number
		int a = 10;
		int b = 20;
		Console.Write("\n Before Swap a : " + a + " b : " + b);
		// Perform swap operation
		a = a ^ b;
		b = a ^ b;
		a = a ^ b;
		// After swaps
		Console.Write("\n  After Swap a : " + a + " b : " + b);
	}
}

Output

 Before Swap a : 10 b : 20
  After Swap a : 20 b : 10
<?php
/*
  Php program
  Swap two numbers using bitwise operator
*/
function main()
{
	// Number
	$a = 10;
	$b = 20;
	echo "\n Before Swap a : ". $a ." b : ". $b;
	// Perform swap operation
	$a = $a ^ $b;
	$b = $a ^ $b;
	$a = $a ^ $b;
	// After swaps
	echo "\n  After Swap a : ". $a ." b : ". $b;
}
main();

Output

 Before Swap a : 10 b : 20
  After Swap a : 20 b : 10
/*
  Node Js program
  Swap two numbers using bitwise operator
*/
function swapping()
{
	// Number
	var a = 10;
	var b = 20;
	process.stdout.write("\n Before Swap a : " + a + " b : " + b);
	// Perform swap operation
	a = a ^ b;
	b = a ^ b;
	a = a ^ b;
	// After swaps
	process.stdout.write("\n  After Swap a : " + a + " b : " + b);
}
swapping();

Output

 Before Swap a : 10 b : 20
  After Swap a : 20 b : 10
#   Python 3 program
#   Swap two numbers using bitwise operator


def swapping() :
	#  Number
	a = 10
	b = 20
	print("\n Before Swap a : ", a ," b : ", b, end = "")
	#  Perform swap operation
	a = a ^ b
	b = a ^ b
	a = a ^ b
	#  After swaps
	print("\n  After Swap a : ", a ," b : ", b, end = "")

if __name__ == "__main__": swapping()

Output

 Before Swap a :  10  b :  20
  After Swap a :  20  b :  10
#   Ruby program
#   Swap two numbers using bitwise operator

def swapping() 
	#  Number
	a = 10
	b = 20
	print("\n Before Swap a : ", a ," b : ", b)
	#  Perform swap operation
	a = a ^ b
	b = a ^ b
	a = a ^ b
	#  After swaps
	print("\n  After Swap a : ", a ," b : ", b)
end

swapping()

Output

 Before Swap a : 10 b : 20
  After Swap a : 20 b : 10
/*
  Scala program
  Swap two numbers using bitwise operator
*/

object Main
{
	def main(args: Array[String]): Unit = {
		// Number
		var a: Int = 10;
		var b: Int = 20;
		print("\n Before Swap a : " + a + " b : " + b);
		// Perform swap operation
		a = a ^ b;
		b = a ^ b;
		a = a ^ b;
		// After swaps
		print("\n  After Swap a : " + a + " b : " + b);
	}
}

Output

 Before Swap a : 10 b : 20
  After Swap a : 20 b : 10
/*
  Swift 4 program
  Swap two numbers using bitwise operator
*/

func main()
{
	// Number
	var a: Int = 10;
	var b: Int = 20;
	print("\n Before Swap a : ", a ," b : ", b, terminator: "");
	// Perform swap operation
	a = a ^ b;
	b = a ^ b;
	a = a ^ b;
	// After swaps
	print("\n  After Swap a : ", a ," b : ", b, terminator: "");
}
main();

Output

 Before Swap a :  10  b :  20
  After Swap a :  20  b :  10
/*
  Kotlin program
  Swap two numbers using bitwise operator
*/

fun main(args: Array <String> ): Unit
{
	// Number
	var a: Int = 10;
	var b: Int = 20;
	print("\n Before Swap a : " + a + " b : " + b);
	// Perform swap operation
	a = a xor b;
	b = a xor b;
	a = a xor b;
	// After swaps
	print("\n  After Swap a : " + a + " b : " + b);
}

Output

 Before Swap a : 10 b : 20
  After Swap a : 20 b : 10

Resultant Output Explanation:

Using the provided code, let's see the output:

Before Swap  a : 10  b : 20
After Swap   a : 20  b : 10

As we can see, the values of a and b have been successfully swapped using bitwise XOR.

Time Complexity:

The time complexity of this code is O(1), which means it has constant time complexity. The bitwise XOR operation takes a constant amount of time to perform regardless of the input values because it directly manipulates the individual bits of the numbers. Hence, the time complexity remains constant.

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