Highest power of 2 that divides a number represented in binary

Given a binary string str, the task is to find the largest power of 2 that divides the decimal equivalent of the given binary number.

Examples:

Input: str = “100100”
Output: 2
2² = 4 is the highest power of 2 that divides 36 (100100).

Input: str = “10010”
Output: 1

Approach: Starting from the right, count the number of 0s in the binary representation which is the highest power of 2 which will divide the number.

Below is the implementation of the above approach:

C++

// C++ implementation of the approach
#include <bits/stdc++.h>
using namespace std;

// Function to return the highest power of 2
// which divides the given binary number
int highestPower(string str, int len)
{

    // To store the highest required power of 2
    int ans = 0;

    // Counting number of consecutive zeros
    // from the end in the given binary string
    for (int i = len - 1; i >= 0; i--) {
        if (str[i] == '0')
            ans++;
        else
            break;
    }

    return ans;
}

// Driver code
int main()
{
    string str = "100100";
    int len = str.length();
    cout << highestPower(str, len);

    return 0;
}

Java

// Java implementation of the approach
class GFG
{

// Function to return the highest power of 2
// which divides the given binary number
static int highestPower(String str, int len)
{

    // To store the highest required power of 2
    int ans = 0;

    // Counting number of consecutive zeros
    // from the end in the given binary string
    for (int i = len - 1; i >= 0; i--)
    {
        if (str.charAt(i) == '0')
            ans++;
        else
            break;
    }

    return ans;
}

// Driver code
public static void main(String[] args)
{
    String str = "100100";
    int len = str.length();
    System.out.println(highestPower(str, len));
}
}

// This code is contributed by Code_Mech.

Python3

# Python3 implementation of the approach

# Function to return the highest power of 2
# which divides the given binary number
def highestPower(str, lenngth):

    # To store the highest required power of 2
    ans = 0;

    # Counting number of consecutive zeros
    # from the end in the given binary string
    for i in range(lenngth-1,-1,-1):
        if (str[i] == '0'):
            ans+=1;
        else:
            break;
    return ans;

# Driver code
def main():
    str = "100100";
    lenngth = len(str);
    print(highestPower(str, lenngth));

if __name__ == '__main__':
    main()

# This code contributed by PrinciRaj1992

C#

// C# implementation of the approach
using System;

class GFG
{

// Function to return the highest power of 2
// which divides the given binary number
static int highestPower(String str, int len)
{

    // To store the highest required power of 2
    int ans = 0;

    // Counting number of consecutive zeros
    // from the end in the given binary string
    for (int i = len - 1; i >= 0; i--)
    {
        if (str[i] == '0')
            ans++;
        else
            break;
    }

    return ans;
}

// Driver code
public static void Main(String[] args)
{
    String str = "100100";
    int len = str.Length;
    Console.WriteLine(highestPower(str, len));
}
}

/* This code contributed by PrinciRaj1992 */

PHP

<?php
// PHP implementation of the approach

// Function to return the highest power of 2
// which divides the given binary number
function highestPower($str, $len)
{

    // To store the highest required power of 2
    $ans = 0;

    // Counting number of consecutive zeros
    // from the end in the given binary string
    for ($i = $len - 1; $i >= 0; $i--)
    {
        if ($str[$i] == '0')
            $ans++;
        else
            break;
    }

    return $ans;
}

// Driver code
$str = "100100";
$len = strlen($str);
echo highestPower($str, $len);

// This code is contributed by Ryuga
?>

Output:

2