XOR counts of 0s and 1s in binary representation

Given a number, the task is to find XOR of count of 0s and count of 1s in binary representation of a given number.
Examples:

Input  : 5
Output : 3
Binary representation : 101
Count of 0s = 1, 
Count of 1s = 2
1 XOR 2 = 3.

Input  : 7
Output : 3
Binary representation : 111
Count of 0s = 0
Count of 1s = 3
0 XOR 3 = 3.

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

The idea is simple, we traverse through all bits of a number, count 0s and 1s and finally return XOR of two counts.

C++

// C++ program to find XOR of counts 0s and 1s in 
// binary representation of n. 
#include<iostream> 
using namespace std; 
  
// Returns XOR of counts 0s and 1s in 
// binary representation of n. 
int countXOR(int n) 
{ 
    int count0 = 0, count1 = 0; 
    while (n) 
    { 
        //calculating count of zeros and ones 
        (n % 2 == 0) ? count0++ :count1++; 
        n /= 2; 
    } 
    return (count0 ^ count1); 
} 
  
// Driver Program 
int main() 
{ 
    int n = 31; 
    cout << countXOR (n); 
    return 0; 
} 

Java

// Java program to find XOR of counts 0s  
// and 1s in binary representation of n. 
  
class GFG { 
      
    // Returns XOR of counts 0s and 1s  
    // in binary representation of n. 
    static int countXOR(int n) 
    { 
        int count0 = 0, count1 = 0; 
        while (n != 0) 
        { 
            //calculating count of zeros and ones 
            if(n % 2 == 0)  
            count0++ ; 
            else
            count1++; 
            n /= 2; 
        } 
        return (count0 ^ count1); 
    } 
      
    // Driver Program 
    public static void main(String[] args) 
    { 
        int n = 31; 
        System.out.println(countXOR (n)); 
    } 
} 
  
// This code is contributed by prerna saini 

Python3

# Python3 program to find XOR of counts 0s  
# and 1s in binary representation of n. 
  
# Returns XOR of counts 0s and 1s  
# in binary representation of n. 
def countXOR(n): 
      
    count0, count1 = 0, 0
    while (n != 0): 
      
        # calculating count of zeros and ones 
        if(n % 2 == 0):  
            count0 += 1
        else: 
            count1 += 1
        n //= 2
          
    return (count0 ^ count1) 
      
# Driver Code 
n = 31
print(countXOR(n)) 
  
# This code is contributed by Anant Agarwal. 

C#

// C# program to find XOR of counts 0s  
// and 1s in binary representation of n. 
using System; 
  
class GFG { 
       
    // Returns XOR of counts 0s and 1s  
    // in binary representation of n. 
    static int countXOR(int n) 
    { 
        int count0 = 0, count1 = 0; 
        while (n != 0) 
        { 
              
            // calculating count of zeros  
            // and ones 
            if(n % 2 == 0)  
                count0++ ; 
            else
                count1++; 
                  
            n /= 2; 
        } 
          
        return (count0 ^ count1); 
    } 
       
    // Driver Program 
    public static void Main() 
    { 
          
        int n = 31; 
          
        Console.WriteLine(countXOR (n)); 
    } 
} 
  
// This code is contributed by Anant Agarwal. 

PHP

<?PHP 
// PHP program to find XOR of  
// counts 0s and 1s in binary  
// representation of n. 
  
// Returns XOR of counts 0s and 1s  
// in binary representation of n. 
function countXOR($n) 
{ 
    $count0 = 0; 
    $count1 = 0; 
    while ($n) 
    { 
        // calculating count of  
        // zeros and ones 
        ($n % 2 == 0) ? $count0++ :$count1++; 
        $n = intval($n / 2); 
    } 
    return ($count0 ^ $count1); 
} 
  
// Driver Code 
$n = 31; 
echo countXOR ($n); 
  
// This code is contributed 
// by ChitraNayal 
?> 

Output:

One observation is, for a number of the form 2^x – 1, the output is always x. We can directly produce answer for this case by first checking n+1 is a power of two or not.

This article is contributed by Shivam Pradhan (anuj_charm). If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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My Personal Notes

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

C++

Java

Python3

C#

PHP

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