Skip to main content

Find nearest power of 2 less than or equal to a number

Here given code implementation process.

// C program 
// Find nearest power of 2 less than or equal to a number
#include <stdio.h>

// Find nearest power of given number
void nearestPower2(int num)
{
	int n = num;
	// First set all bits
	n = n | n >> 1;
	n = n | n >> 2;
	n = n | n >> 4;
	n = n | n >> 8;
	n = n | n >> 16;
	// Get final result
	// n are indicates all active bits of given a number
	// So shift n one by left and perform xor operation
	n = n ^ (n >> 1);
	// Display calculated result
	printf("\n Number :  %d", num);
	printf("\n Power  :  %d\n", n);
}
int main(int argc, char
	const *argv[])
{
	// Test Cases
	nearestPower2(10);
	nearestPower2(31);
	nearestPower2(64);
	nearestPower2(43);
	return 0;
}

Output

 Number :  10
 Power  :  8

 Number :  31
 Power  :  16

 Number :  64
 Power  :  64

 Number :  43
 Power  :  32
/*
  Java program
  Find nearest power of 2 less than or equal to a number
*/
public class Power
{
   
    // Find nearest power of given number
    public void nearestPower2(int num)
    {
        int n = num;
        // First set all bits
        n = n | n >> 1;
        n = n | n >> 2;
        n = n | n >> 4;
        n = n | n >> 8;
        n = n | n >> 16;
        // Get final result
        // n are indicates all active bits of given a number
        // So shift n one by left and perform xor operation
        n = n ^ (n >> 1);
        // Display calculated result
        System.out.print("\n Number : " + num );
        System.out.print("\n Power : " + n + "\n");
    }

    public static void main(String[] args)
    {
        Power task = new Power();
        // Test Cases
        task.nearestPower2(10);
        task.nearestPower2(31);
        task.nearestPower2(64);
        task.nearestPower2(43);
    }
}

Output

 Number : 10
 Power : 8

 Number : 31
 Power : 16

 Number : 64
 Power : 64

 Number : 43
 Power : 32
// Include header file
#include <iostream>
using namespace std;

/*
  C++ program
  Find nearest power of 2 less than or equal to a number
*/

class Power
{
	public:
		// Find nearest power of given number
		void nearestPower2(int num)
		{
			int n = num;
			// First set all bits
			n = n | n >> 1;
			n = n | n >> 2;
			n = n | n >> 4;
			n = n | n >> 8;
			n = n | n >> 16;
			// Get final result
			// n are indicates all active bits of given a number
			// So shift n one by left and perform xor operation
			n = n ^ (n >> 1);
			// Display calculated result
			cout << "\n Number : " << num;
			cout << "\n Power : " << n << "\n";
		}
};
int main()
{
	Power task = Power();
	// Test Cases
	task.nearestPower2(10);
	task.nearestPower2(31);
	task.nearestPower2(64);
	task.nearestPower2(43);
	return 0;
}

Output

 Number : 10
 Power : 8

 Number : 31
 Power : 16

 Number : 64
 Power : 64

 Number : 43
 Power : 32
// Include namespace system
using System;
/*
  C# program
  Find nearest power of 2 less than or equal to a number
*/
public class Power
{
	// Find nearest power of given number
	public void nearestPower2(int num)
	{
		int n = num;
		// First set all bits
		n = n | n >> 1;
		n = n | n >> 2;
		n = n | n >> 4;
		n = n | n >> 8;
		n = n | n >> 16;
		// Get final result
		// n are indicates all active bits of given a number
		// So shift n one by left and perform xor operation
		n = n ^ (n >> 1);
		// Display calculated result
		Console.Write("\n Number : " + num);
		Console.Write("\n Power : " + n + "\n");
	}
	public static void Main(String[] args)
	{
		Power task = new Power();
		// Test Cases
		task.nearestPower2(10);
		task.nearestPower2(31);
		task.nearestPower2(64);
		task.nearestPower2(43);
	}
}

Output

 Number : 10
 Power : 8

 Number : 31
 Power : 16

 Number : 64
 Power : 64

 Number : 43
 Power : 32
<?php
/*
  Php program
  Find nearest power of 2 less than or equal to a number
*/
class Power
{
	// Find nearest power of given number
	public	function nearestPower2($num)
	{
		$n = $num;
		// First set all bits
		$n = $n | $n >> 1;
		$n = $n | $n >> 2;
		$n = $n | $n >> 4;
		$n = $n | $n >> 8;
		$n = $n | $n >> 16;
		// Get final result
		// n are indicates all active bits of given a number
		// So shift n one by left and perform xor operation
		$n = $n ^ ($n >> 1);
		// Display calculated result
		echo "\n Number : ". $num;
		echo "\n Power : ". $n ."\n";
	}
}

function main()
{
	$task = new Power();
	// Test Cases
	$task->nearestPower2(10);
	$task->nearestPower2(31);
	$task->nearestPower2(64);
	$task->nearestPower2(43);
}
main();

Output

 Number : 10
 Power : 8

 Number : 31
 Power : 16

 Number : 64
 Power : 64

 Number : 43
 Power : 32
/*
  Node Js program
  Find nearest power of 2 less than or equal to a number
*/
class Power
{
	// Find nearest power of given number
	nearestPower2(num)
	{
		var n = num;
		// First set all bits
		n = n | n >> 1;
		n = n | n >> 2;
		n = n | n >> 4;
		n = n | n >> 8;
		n = n | n >> 16;
		// Get final result
		// n are indicates all active bits of given a number
		// So shift n one by left and perform xor operation
		n = n ^ (n >> 1);
		// Display calculated result
		process.stdout.write("\n Number : " + num);
		process.stdout.write("\n Power : " + n + "\n");
	}
}

function main()
{
	var task = new Power();
	// Test Cases
	task.nearestPower2(10);
	task.nearestPower2(31);
	task.nearestPower2(64);
	task.nearestPower2(43);
}
main();

Output

 Number : 10
 Power : 8

 Number : 31
 Power : 16

 Number : 64
 Power : 64

 Number : 43
 Power : 32
#   Python 3 program
#   Find nearest power of 2 less than or equal to a number

class Power :
	#  Find nearest power of given number
	def nearestPower2(self, num) :
		n = num
		#  First set all bits
		n = n | n >> 1
		n = n | n >> 2
		n = n | n >> 4
		n = n | n >> 8
		n = n | n >> 16
		#  Get final result
		#  n are indicates all active bits of given a number
		#  So shift n one by left and perform xor operation
		n = n ^ (n >> 1)
		#  Display calculated result
		print("\n Number : ", num, end = "")
		print("\n Power : ", n )
	

def main() :
	task = Power()
	#  Test Cases
	task.nearestPower2(10)
	task.nearestPower2(31)
	task.nearestPower2(64)
	task.nearestPower2(43)

if __name__ == "__main__": main()

Output

 Number :  10
 Power :  8

 Number :  31
 Power :  16

 Number :  64
 Power :  64

 Number :  43
 Power :  32
#   Ruby program
#   Find nearest power of 2 less than or equal to a number

class Power 
	#  Find nearest power of given number
	def nearestPower2(num) 
		n = num
		#  First set all bits
		n = n | n >> 1
		n = n | n >> 2
		n = n | n >> 4
		n = n | n >> 8
		n = n | n >> 16
		#  Get final result
		#  n are indicates all active bits of given a number
		#  So shift n one by left and perform xor operation
		n = n ^ (n >> 1)
		#  Display calculated result
		print("\n Number : ", num)
		print("\n Power : ", n ,"\n")
	end

end

def main() 
	task = Power.new()
	#  Test Cases
	task.nearestPower2(10)
	task.nearestPower2(31)
	task.nearestPower2(64)
	task.nearestPower2(43)
end

main()

Output

 Number : 10
 Power : 8

 Number : 31
 Power : 16

 Number : 64
 Power : 64

 Number : 43
 Power : 32

/*
  Scala program
  Find nearest power of 2 less than or equal to a number
*/
class Power
{
	// Find nearest power of given number
	def nearestPower2(num: Int): Unit = {
		var n: Int = num;
		// First set all bits
		n = n | n >> 1;
		n = n | n >> 2;
		n = n | n >> 4;
		n = n | n >> 8;
		n = n | n >> 16;
		// Get final result
		// n are indicates all active bits of given a number
		// So shift n one by left and perform xor operation
		n = n ^ (n >> 1);
		// Display calculated result
		print("\n Number : " + num);
		print("\n Power : " + n + "\n");
	}
}
object Main
{
	def main(args: Array[String]): Unit = {
		var task: Power = new Power();
		// Test Cases
		task.nearestPower2(10);
		task.nearestPower2(31);
		task.nearestPower2(64);
		task.nearestPower2(43);
	}
}

Output

 Number : 10
 Power : 8

 Number : 31
 Power : 16

 Number : 64
 Power : 64

 Number : 43
 Power : 32
/*
  Swift 4 program
  Find nearest power of 2 less than or equal to a number
*/
class Power
{
	// Find nearest power of given number
	func nearestPower2(_ num: Int)
	{
		var n: Int = num;
		// First set all bits
		n = n | n >> 1;
		n = n | n >> 2;
		n = n | n >> 4;
		n = n | n >> 8;
		n = n | n >> 16;
		// Get final result
		// n are indicates all active bits of given a number
		// So shift n one by left and perform xor operation
		n = n ^ (n >> 1);
		// Display calculated result
		print("\n Number : ", num, terminator: "");
		print("\n Power : ", n );
	}
}
func main()
{
	let task: Power = Power();
	// Test Cases
	task.nearestPower2(10);
	task.nearestPower2(31);
	task.nearestPower2(64);
	task.nearestPower2(43);
}
main();

Output

 Number :  10
 Power :  8

 Number :  31
 Power :  16

 Number :  64
 Power :  64

 Number :  43
 Power :  32
/*
  Kotlin program
  Find nearest power of 2 less than or equal to a number
*/
class Power
{
	// Find nearest power of given number
	fun nearestPower2(num: Int): Unit
	{
		var n: Int = num;
		// First set all bits
		n = n or (n shr 1);
		n = n or (n shr 2);
		n = n or (n shr 4);
		n = n or (n shr 8);
		n = n or (n shr 16);
		// Get final result
		// n are indicates all active bits of given a number
		// So shift n one by left and perform xor operation
		n = n xor (n shr 1);
		// Display calculated result
		print("\n Number : " + num);
		print("\n Power : " + n + "\n");
	}
}
fun main(args: Array <String> ): Unit
{
	var task: Power = Power();
	// Test Cases
	task.nearestPower2(10);
	task.nearestPower2(31);
	task.nearestPower2(64);
	task.nearestPower2(43);
}

Output

 Number : 10
 Power : 8

 Number : 31
 Power : 16

 Number : 64
 Power : 64

 Number : 43
 Power : 32
Last updated on by Kalkicode




Comment

Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.

New Comment