Binary to Gray code using recursion

Given Binary code of a number as a decimal number, we need to convert this into its equivalent Gray Code.

Examples :

Input : 1001 
Output : 1101

Input : 11
Output : 10

In gray code, only one bit is changed in 2 consecutive numbers.

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Algorithm :

binary_to_grey(n)
 if n == 0
       grey = 0;
 else if last two bits are opposite  to each other
       grey = 1 + 10 * binary_to_gray(n/10))
 else if last two bits are same
       grey = 10 * binary_to_gray(n/10))

Below is implementation of above approach :

CPP

// CPP program to convert Binary to  
// Gray code using recursion 
#include <bits/stdc++.h> 
using namespace std; 
  
// Function to change Binary to 
// Gray using recursion 
int binary_to_gray(int n) 
{  
    if (!n)  
        return 0; 
  
    // Taking last digit 
    int a = n % 10;  
      
    // Taking second last digit 
    int b = (n / 10) % 10;  
          
    // If last digit are opposite bits 
    if ((a && !b) || (!a && b))          
            return (1 + 10 * binary_to_gray(n / 10)); 
          
    // If last two bits are same 
    return (10 * binary_to_gray(n / 10)); 
} 
  
// Driver Function 
int main() 
{ 
    int binary_number = 1011101; 
      
    printf("%d", binary_to_gray(binary_number)); 
    return 0; 
} 

Java

// Java program to convert 
// Binary code to Gray code 
import static java.lang.StrictMath.pow; 
import java.util.Scanner; 
  
class bin_gray 
{ 
    // Function to change Binary to 
    // Gray using recursion 
    int binary_to_gray(int n, int i) 
    {  
        int a, b; 
        int result = 0; 
        if (n != 0)  
        { 
            // Taking last digit 
            a = n % 10;  
              
            n = n / 10; 
              
            // Taking second last digit 
            b = n % 10;  
          
            if ((a & ~ b) == 1 || (~ a & b) == 1)  
            { 
                result = (int) (result + pow(10,i)); 
            } 
              
            return binary_to_gray(n, ++i) + result; 
        } 
        return 0; 
    } 
  
    // Driver Function 
    public static void main(String[] args) 
    { 
        int binary_number; 
        int result = 0; 
        binary_number = 1011101; 
          
        bin_gray obj = new bin_gray(); 
        result = obj.binary_to_gray(binary_number,0); 
          
        System.out.print(result); 
    }  
} 
  
// This article is contributed by Anshika Goyal. 

Python3

# Python3 code to convert Binary 
# to Gray code using recursion 
  
# Function to change Binary to Gray using recursion 
def binary_to_gray( n ): 
    if not(n): 
        return 0
          
    # Taking last digit     
    a = n % 10
      
     # Taking second last digit 
    b = int(n / 10) % 10
      
    # If last digit are opposite bits 
    if (a and not(b)) or (not(a) and b): 
        return (1 + 10 * binary_to_gray(int(n / 10))) 
      
    # If last two bits are same 
    return (10 * binary_to_gray(int(n / 10))) 
  
# Driver Code 
binary_number = 1011101
print( binary_to_gray(binary_number), end='') 
  
# This code is contributed by "Sharad_Bhardwaj". 

C#

// C# program to convert 
// Binary code to Gray code 
using System; 
  
class GFG { 
      
    // Function to change Binary to 
    // Gray using recursion 
    static int binary_to_gray(int n, int i) 
    {  
        int a, b; 
        int result = 0; 
        if (n != 0)  
        { 
              
            // Taking last digit 
            a = n % 10;  
              
            n = n / 10; 
              
            // Taking second last digit 
            b = n % 10;  
          
            if ((a & ~ b) == 1 || (~ a & b) == 1)  
            { 
                result = (int) (result + Math.Pow(10,i)); 
            } 
              
            return binary_to_gray(n, ++i) + result; 
        } 
          
        return 0; 
    } 
  
    // Driver Function 
    public static void Main() 
    { 
        int binary_number; 
        binary_number = 1011101; 
          
        Console.WriteLine(binary_to_gray(binary_number,0)); 
    }  
} 
  
// This article is contributed by vt_m. 

PHP

<?php 
// PHP program to convert Binary to  
// Gray code using recursion 
  
// Function to change Binary to 
// Gray using recursion 
function binary_to_gray($n) 
{  
    if (!$n)  
        return 0; 
  
    // Taking last digit 
    $a = $n % 10;  
      
    // Taking second  
    // last digit 
    $b = ($n / 10) % 10;  
          
    // If last digit are  
    // opposite bits 
    if (($a && !$b) || (!$a && $b))      
            return (1 + 10 * binary_to_gray($n / 10)); 
          
    // If last two  
    // bits are same 
    return (10 * binary_to_gray($n / 10)); 
} 
  
    // Driver Code 
    $binary_number = 1011101; 
    echo binary_to_gray($binary_number); 
  
// This code is contributed by Ajit 
?> 

Output :

Assume that the binary number is in the range of integer. For larger value we can take binary number as string.

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My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

CPP

Java

Python3

C#

PHP

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