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++

 // 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

 // 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

 # 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#

 // 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

PHP

 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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