# Highest power of two that divides a given number

Given a number n, find the highest power of 2 that divides n.

Examples:

Input : n = 48
Output : 16
Highest power of 2 that divides 48 is 16.

Input : n = 5
Output : 1
Highest power of 2 that divides 5 is 1.

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

A simple solution is to try all powers of 2 one by one starting from 1, then 2, then 4 and so on.

An efficient solution is based on bit magic. If we take a closer look, we can notice that, we basically need to find the number that has rightmost bit set at same position as n and all other bits as 0. For example, for n = 5 (101), our output is 001. For n = 48 (110000), our output is 010000
How do we find a number that has same rightmost set bit and all other bits as 0?

Let n = 48 (00110000)
Subtract one from n, i.e., we do n-1. We get 47(00101111)
Do negation of (n-1), i.e., we do ~(n-1). We get (11010000).
Do n & (~(n-1)), we get 00010000 which has value 16.

Below is the implementation of above approach:

## C++

 `// CPP program to find highest power ` `// of 2 that divides n. ` `#include ` `using` `namespace` `std; ` ` `  `int` `highestPowerOf2(``int` `n) ` `{ ` `    ``return` `(n & (~(n - 1))); ` `} ` ` `  `int` `main() ` `{  ` `    ``int` `n = 48; ` `    ``cout << highestPowerOf2(n); ` `    ``return` `0; ` `} `

## Java

 `// Java program to find highest power ` `// of 2 that divides n. ` `  `  `class` `GFG ` `{ ` `      `  `static` `int` `highestPowerOf2(``int` `n) ` `{ ` `    ``return` `(n & (~(n - ``1``))); ` `} ` `  `  `public` `static` `void` `main(String []args) ` `{  ` `    ``int` `n = ``48``; ` `    ``System.out.println(highestPowerOf2(n)); ` `} ` `} ` ` `

## Python3

 `# Python3 program to find highest power  ` `# of 2 that divides n.  ` ` `  `def` `highestPowerOf2(n):  ` ` `  `    ``return` `(n & (~(n ``-` `1``)))  ` ` `  ` `  `#Driver code ` `if` `__name__``=``=``'__main__'``: ` `    ``n ``=` `48` `    ``print``(highestPowerOf2(n))  ` ` `  `# this code is contributed  ` `# by ash264 `

## C#

 `// C# program to find highest power ` `// of 2 that divides n. ` `using` `System; ` ` `  `class` `GFG ` `{ ` `     `  `static` `int` `highestPowerOf2(``int` `n) ` `{ ` `    ``return` `(n & (~(n - 1))); ` `} ` ` `  `public` `static` `void` `Main() ` `{  ` `    ``int` `n = 48; ` `    ``Console.Write(highestPowerOf2(n)); ` `} ` `} ` ` `  `// This code is contributed ` `// by Akanksha Rai(Abby_akku) `

## PHP

 ` `

Output:

```16
```

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