# Smallest perfect power of 2 greater than n (without using arithmetic operators)

Given a non-negative integer n. The problem is to find the smallest perfect power of 2 which is greater than n without using the arithmetic operators.

Examples :

```Input : n = 10
Output : 16

Input : n = 128
Output : 256
```

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

Algorithm :

 `// C++ implementation of smallest perfect power ` `// of 2 greater than n ` `#include ` ` `  `using` `namespace` `std; ` ` `  `// Function to find smallest perfect power ` `// of 2 greater than n ` `unsigned ``int` `perfectPowerOf2(unsigned ``int` `n) ` `{ ` `    ``// To store perfect power of 2 ` `    ``unsigned ``int` `per_pow = 1; ` ` `  `    ``while` `(n > 0)  ` `    ``{ ` `        ``// bitwise left shift by 1 ` `        ``per_pow = per_pow << 1; ` ` `  `        ``// bitwise right shift by 1 ` `        ``n = n >> 1; ` `    ``} ` ` `  `    ``// Required perfect power of 2 ` `    ``return` `per_pow; ` `} ` ` `  `// Driver program to test above ` `int` `main() ` `{ ` `    ``unsigned ``int` `n = 128; ` `    ``cout << ``"Perfect power of 2 greater than "` `        ``<< n << ``": "` `<< perfectPowerOf2(n); ` `    ``return` `0; ` `} `

 `// JAVA Code for Smallest perfect ` `// power of 2 greater than n ` `import` `java.util.*; ` ` `  `class` `GFG { ` `     `  `    ``// Function to find smallest perfect ` `    ``// power of 2 greater than n ` `    ``static` `int` `perfectPowerOf2( ``int` `n) ` `    ``{ ` `        ``// To store perfect power of 2 ` `         ``int` `per_pow = ``1``; ` `      `  `        ``while` `(n > ``0``)  ` `        ``{ ` `            ``// bitwise left shift by 1 ` `            ``per_pow = per_pow << ``1``; ` `             `  `            ``n = n >> ``1``; ` `        ``} ` `      `  `        ``// Required perfect power of 2 ` `        ``return` `per_pow; ` `    ``} ` `     `  `    ``// Driver program ` `    ``public` `static` `void` `main(String[] args)  ` `    ``{ ` `         ``int` `n = ``12``; ` `         ``System.out.println(``"Perfect power of 2 greater than "` `                            ``+ n + ``": "` `+ perfectPowerOf2(n)); ` `        ``} ` `    ``} ` `         `  `    ``//This code is contributed by Arnav Kr. Mandal. `

 `# Python3 implementation of smallest  ` `# perfect power of 2 greater than n ` ` `  `# Function to find smallest perfect  ` `# power of 2 greater than n ` `def` `perfectPowerOf2( n ): ` `     `  `    ``# To store perfect power of 2 ` `    ``per_pow ``=` `1` `     `  `    ``while` `n > ``0``: ` `     `  `        ``# bitwise left shift by 1 ` `        ``per_pow ``=` `per_pow << ``1` `         `  `        ``# bitwise right shift by 1 ` `        ``n ``=` `n >> ``1` `         `  `    ``# Required perfect power of 2 ` `    ``return` `per_pow ` ` `  `# Driver program to test above ` `n ``=` `128` `print``(``"Perfect power of 2 greater than"``, ` `            ``n, ``":"``,perfectPowerOf2(n)) ` ` `  `# This code is contributed by "Sharad_Bhardwaj". `

 `// C# Code for Smallest perfect ` `// power of 2 greater than n ` `using` `System; ` ` `  `class` `GFG { ` ` `  `    ``// Function to find smallest perfect ` `    ``// power of 2 greater than n ` `    ``static` `int` `perfectPowerOf2(``int` `n) ` `    ``{ ` `        ``// To store perfect power of 2 ` `        ``int` `per_pow = 1; ` ` `  `        ``while` `(n > 0)  ` `        ``{ ` `            ``// bitwise left shift by 1 ` `            ``per_pow = per_pow << 1; ` ` `  `            ``n = n >> 1; ` `        ``} ` ` `  `        ``// Required perfect power of 2 ` `        ``return` `per_pow; ` `    ``} ` ` `  `    ``// Driver program ` `    ``public` `static` `void` `Main() ` `    ``{ ` `        ``int` `n = 128; ` `        ``Console.WriteLine(``"Perfect power of 2 greater than "` `+ ` `                           ``n + ``": "` `+ perfectPowerOf2(n)); ` `    ``} ` `} ` ` `  `// This code is contributed by Sam007 `

 ` 0)  ` `    ``{ ` `        ``// bitwise left shift by 1 ` `        ``\$per_pow` `= ``\$per_pow` `<< 1; ` ` `  `        ``// bitwise right shift by 1 ` `        ``\$n` `= ``\$n` `>> 1; ` `    ``} ` ` `  `    ``// Required perfect power of 2 ` `    ``return` `\$per_pow``; ` `} ` ` `  `    ``// Driver code ` `    ``\$n` `= 128; ` `    ``echo` `"Perfect power of 2 greater than "``.  ` `          ``\$n` `. ``": "``.perfectPowerOf2(``\$n``); ` ` `  `// This code is contributed by mits  ` `?> `

Output:
```Perfect power of 2 greater than 128: 256
```

Time Complexity: O(num), where num is the number of bits in the binary representation of n.

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Improved By : Mithun Kumar

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