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Binary representation of a given number
  • Difficulty Level : Easy
  • Last Updated : 31 Mar, 2021

Write a program to print Binary representation of a given number. 

Source: Microsoft Interview Set-3 

Method 1: Iterative 
For any number, we can check whether its ‘i’th bit is 0(OFF) or 1(ON) by bitwise ANDing it with “2^i” (2 raise to i). 

1) Let us take number 'NUM' and we want to check whether it's 0th bit is ON or OFF    
    bit = 2 ^ 0 (0th bit)
    if  NUM & bit == 1 means 0th bit is ON else 0th bit is OFF

2) Similarly if we want to check whether 5th bit is ON or OFF    
    bit = 2 ^ 5 (5th bit)
    if NUM & bit == 1 means its 5th bit is ON else 5th bit is OFF.

Let us take unsigned integer (32 bit), which consist of 0-31 bits. To print binary representation of unsigned integer, start from 31th bit, check whether 31th bit is ON or OFF, if it is ON print “1” else print “0”. Now check whether 30th bit is ON or OFF, if it is ON print “1” else print “0”, do this for all bits from 31 to 0, finally we will get binary representation of number.

C++




// C++ Program for the binary
// representation of a given number
#include <bits/stdc++.h>
using namespace std;
 
  void bin(long n)
  {
    long i;
    cout << "0";
    for (i = 1 << 30; i > 0; i = i / 2)
    {
      if((n & i) != 0)
      {
        cout << "1";
      }
      else
      {
        cout << "0";
      }
    }
  }
 
// Driver Code
int main(void)
{
    bin(7);
    cout << endl;
    bin(4);
}
 
// This code is contributed by souravghosh0416

C




#include<stdio.h>
void bin(unsigned n)
{
    unsigned i;
    for (i = 1 << 31; i > 0; i = i / 2)
        (n & i) ? printf("1") : printf("0");
}
 
int main(void)
{
    bin(7);
    printf("\n");
    bin(4);
}

Java




public class GFG
{
  static void bin(long n)
  {
    long i;
    System.out.print("0");
    for (i = 1 << 30; i > 0; i = i / 2)
    {
      if((n & i) != 0)
      {
        System.out.print("1");
      }
      else
      {
        System.out.print("0");
      }
    }
  }
 
  // Driver code
  public static void main(String[] args)
  {
    bin(7);
    System.out.println();
    bin(4);
  }
}
 
// This code is contributed by divyesh072019.

Python3




def bin(n) :
     
    i = 1 << 31
    while(i > 0) :
     
        if((n & i) != 0) :
         
            print("1", end = "")
         
        else :
            print("0", end = "")
             
        i = i // 2
             
bin(7)
print()
bin(4)
 
# This code is contributed by divyeshrabadiya07.

C#




using System;
 
public class GFG{
    static void bin(long n)
    {
        long i;
        Console.Write("0");
        for (i = 1 << 30; i > 0; i = i / 2)
        {
            if((n & i) != 0)
            {
                Console.Write("1");
            }
            else
            {
                Console.Write("0");
            }
        }
    }
    // Driver code
    static public void Main (){
        bin(7);
        Console.WriteLine();
        bin(4);
    }
}
// This code is contributed by avanitrachhadiya2155

Javascript




<script>
// JavaScript Program for the binary
// representation of a given number
    function bin(n)
    {
        let i;
        document.write("0");
        for (i = 1 << 30; i > 0; i = Math.floor(i/2))
        {
            if((n & i) != 0)
            {
                document.write("1");
            }
            else
            {
                document.write("0");
            }
        }
    }
     
    bin(7);
    document.write("<br>");
    bin(4);
     
     
    // This code is contributed by rag2127
     
</script>
Output



00000000000000000000000000000111
00000000000000000000000000000100

Method 2: Recursive 
Following is recursive method to print binary representation of ‘NUM’. 

step 1) if NUM > 1
    a) push NUM on stack
    b) recursively call function with 'NUM / 2'
step 2)
    a) pop NUM from stack, divide it by 2 and print it's remainder.

C++




// C++ Program for the binary
// representation of a given number
#include <bits/stdc++.h>
using namespace std;
 
void bin(unsigned n)
{
    /* step 1 */
    if (n > 1)
        bin(n / 2);
 
    /* step 2 */
    cout << n % 2;
}
 
// Driver Code
int main(void)
{
    bin(7);
    cout << endl;
    bin(4);
}
 
// This code is contributed
// by Akanksha Rai

C




// C Program for the binary
// representation of a given number
void bin(unsigned n)
{
    /* step 1 */
    if (n > 1)
        bin(n / 2);
 
    /* step 2 */
    printf("%d", n % 2);
}
 
// Driver Code
int main(void)
{
    bin(7);
    printf("\n");
    bin(4);
}

Java




// Java Program for the binary
// representation of a given number
class GFG {
    static void bin(int n)
    {
        /* step 1 */
        if (n > 1)
            bin(n / 2);
 
        /* step 2 */
        System.out.print(n % 2);
    }
 
    // Driver code
    public static void main(String[] args)
    {
        bin(7);
        System.out.println();
        bin(4);
    }
}
 
// This code is contributed
// by ChitraNayal

Python3




# Python3 Program for the binary
# representation of a given number
 
 
def bin(n):
 
    if n > 1:
        bin(n//2)
 
    print(n % 2, end="")
 
 
# Driver Code
if __name__ == "__main__":
 
    bin(7)
    print()
    bin(4)
 
# This code is contributed by ANKITRAI1

C#




// C# Program for the binary
// representation of a given number
using System;
 
class GFG {
 
    static void bin(int n)
    {
 
        // step 1
        if (n > 1)
            bin(n / 2);
 
        // step 2
        Console.Write(n % 2);
    }
 
    // Driver code
    static public void Main()
    {
        bin(7);
        Console.WriteLine();
        bin(4);
    }
}
 
// This code is contributed ajit

PHP




<?php
// PHP Program for the binary
// representation of a given number
function bin($n)
{
    /* step 1 */
    if ($n > 1)
        bin($n/2);
 
    /* step 2 */
    echo ($n % 2);
}
 
// Driver code
bin(7);
echo ("\n");
bin(4);
 
// This code is contributed
// by Shivi_Aggarwal
?>

Javascript




<script>
 
// Javascript program for the binary
// representation of a given number
function bin(n)
{
     
    // Step 1
    if (n > 1)
        bin(parseInt(n / 2, 10));
 
    // Step 2
    document.write(n % 2);
}
 
// Driver code
bin(7);
document.write("</br>");
bin(4);
 
// This code is contributed by divyeshrabadiya07
 
</script>
Output
111
100

Method 3: Recursive using bitwise operator 
Steps to convert decimal number to its binary representation are given below: 

step 1: Check n > 0
step 2: Right shift the number by 1 bit and recursive function call
step 3: Print the bits of number

C++




// C++ implementation of the approach
#include <bits/stdc++.h>
using namespace std;
 
// Function to convert decimal
// to binary number
void bin(unsigned n)
{
    if (n > 1)
        bin(n >> 1);
 
    printf("%d", n & 1);
}
 
// Driver code
int main(void)
{
    bin(131);
    printf("\n");
    bin(3);
    return 0;
}

Java




// Java implementation of the approach
 
class GFG {
 
    // Function to convert decimal
    // to binary number
    static void bin(Integer n)
    {
        if (n > 1)
            bin(n >> 1);
 
        System.out.printf("%d", n & 1);
    }
 
    // Driver code
    public static void main(String[] args)
    {
        bin(131);
        System.out.printf("\n");
        bin(3);
    }
}
/*This code is contributed by PrinciRaj1992*/

Python3




# Python 3 implementation of above approach
 
# Function to convert decimal to
# binary number
 
 
def bin(n):
 
    if (n > 1):
        bin(n >> 1)
    print(n & 1, end="")
 
 
# Driver code
bin(131)
print()
bin(3)
 
# This code is contributed by PrinciRaj1992

C#




// C# implementation of above approach
using System;
 
public class GFG {
 
    // Function to convert decimal
    // to binary number
    static void bin(int n)
    {
        if (n > 1)
            bin(n >> 1);
 
        Console.Write(n & 1);
    }
 
    // Driver code
    public static void Main()
    {
        bin(131);
        Console.WriteLine();
        bin(3);
    }
}
/*This code is contributed by PrinciRaj1992*/

PHP




<?php
// PHP implementation of the approach
 
// Function to convert decimal
// to binary number
function bin($n)
{
    if ($n > 1)
    bin($n>>1);
     
    echo ($n & 1);
}
 
// Driver code
bin(131);
echo "\n";
bin(3);
 
// This code is contributed
// by Akanksha Rai

Javascript




<script>
// JavaScript implementation of the approach
 
// Function to convert decimal
// to binary number
function bin(n)
{
    if (n > 1)
        bin(n >> 1);
 
    document.write(n & 1);
}
 
// Driver code
 
    bin(131);
    document.write("<br>");
    bin(3);
 
 
// This code is contributed by Surbhi Tyagi.
 
</script>
Output
10000011
11

Method 4: Inbuilt library of Python 

Python3




def binary(num):
    return int(bin(num).split('0b')[1])
 
if __name__ == "__main__" :
    x = 10
    binary_x = binary(x)
    print(binary_x)
 
# This code is contributed by Rishika Gupta.
Output
1010

https://youtu.be/p0Vyq2_Q_uI

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
This article is compiled by Narendra Kangralkar

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