java power of 2 - Brave Search

Calculating powers of integers

stackoverflow.com › questions › 8071363 › calculating-powers-of-integers

When it's a power of 2 keep in mind that you can use a simple and fast shift expression: 1 << exponent

For example:

2² = 1 << 2 = (int) Math.pow(2, 2)
2¹⁰ = 1 << 10 = (int) Math.pow(2, 10)

For larger exponents (over 31) use long instead:

2³² = 1L << 32 = (long) Math.pow(2, 32)

BTW, in Kotlin you have shl instead of <<:

(Java) 1L << 32 = 1L shl 32 (Kotlin)

Answer from Stanislaw Baranski on Stack Overflow

stackoverflow.com › questions › 8071363 › calculating-powers-of-integers

java - Calculating powers of integers - Stack Overflow

When it's a power of 2 keep in mind that you can use a simple and fast shift expression: 1 << exponent

For example:

2² = 1 << 2 = (int) Math.pow(2, 2)
2¹⁰ = 1 << 10 = (int) Math.pow(2, 10)

For larger exponents (over 31) use long instead:

2³² = 1L << 32 = (long) Math.pow(2, 32)

BTW, in Kotlin you have shl instead of <<:

(Java) 1L << 32 = 1L shl 32 (Kotlin)

Integers are only 32 bits. This means that its max value is 2^31 -1. As you see, for very small numbers, you quickly have a result which can't be represented by an integer anymore. That's why Math.pow uses double.

If you want arbitrary integer precision, use BigInteger.pow. But it's of course less efficient.

geeksforgeeks.org › java › java-program-to-find-whether-a-no-is-power-of-two

Java Program to find whether a no is power of two - GeeksforGeeks

July 23, 2025 - In any iteration, if n%2 becomes non-zero and n is not 1 then n is not a power of 2. If n becomes 1 then it is a power of 2. ... // Java program to find whether // a no is power of two import java.io.*; class GFG { // Function to check if // ...

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Exercise 4.14 (pow2) Java Tutorial || Practice-It - YouTube

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how to take power of a number in java in eclipse | how to take ...

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w3schools.com › java › ref_math_pow.asp

Java Math pow() Method

Java Examples Java Videos Java ... System.out.println(Math.pow(10, -2)); Try it Yourself » · The pow() method raises a number to the power of another number....

baeldung.com › home › java › check if a number is power of 2 in java

Check if a Number Is Power of 2 in Java | Baeldung

May 14, 2024 - Lastly, we can use the logarithm base 2 to check the power of 2. The base-2 logarithm of a number is the exponent to which 2 must be raised to get that number. If the logarithm (base 2) of a number is a whole number, then the number is a power of 2. ...

Java Code Geeks

javacodegeeks.com › home › core java

Check if a Number Is Power of 2 in Java - Java Code Geeks

July 3, 2024 - We repeatedly divide the number by 2 as long as it is even. Finally, we check if the resulting number is 1. This method utilizes the property that powers of 2 have exactly one bit set in their binary representation.

introcs.cs.princeton.edu › java › 13flow › PowersOfTwo.java.html

PowersOfTwo.java

* ****************************... i equals n while (i <= n) { System.out.println(i + " " + powerOfTwo); // print out the power of two powerOfTwo = 2 * powerOfTwo; // double to get the next one i = i + 1; } } }...

programiz.com › java-programming › examples › power-number

Java Program to Calculate the Power of a Number

In this program, we use Java's Math.pow() function to calculate the power of the given base. We can also compute the power of a negative number using the pow() method. class Main { public static void main(String[] args) { // negative number int base = -3, exponent = 2; double result = ...

codereview.stackexchange.com › questions › 172849 › checking-if-a-number-is-power-of-2-or-not

java - Checking if a number is power of 2 or not - Code Review Stack Exchange

`try-with-resources`

Since Java 7, you should use try-with-resources on your Scanner for safe and efficient handling of the underlying I/O resource:

public static void main(String[] args) {
    try (Scanner scanner = new Scanner(System.in)) {
        int number = scanner.nextInt();
        // other operations
    }
}

Mathematical approach

You may want to consider using a faster mathematical approach to test if the number is a positive power of two or not...

boolean result = number > 0 && ((number & (number - 1)) == 0);

\ $\text{[math]}$ is technically a power of two: \ $\text{[math]}$

There's actually a bit hack for this :

private static boolean isPowerOfTwo(int number) {

    return number > 0 && ((number & (number - 1)) == 0);

}

(ref : Bit Twiddling hacks)

This exploits the fact, that in binary notation a power of two is a 1 followed by a number of 0's, and the number just below is all 1's equal to that number of 0's :

  100000000 // number
& 011111111 // number - 1
-----------
  000000000

Find elsewhere

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leetcode.com › problems › power-of-two

Power of Two - LeetCode

Can you solve this real interview question? Power of Two - Given an integer n, return true if it is a power of two. Otherwise, return false. An integer n is a power of two, if there exists an integer x such that n == 2x.

naukri.com › code360 › library › math-pow-function-in-java

Math pow() Function in Java - Naukri Code 360

Almost there... just a few more seconds

quora.com › How-do-I-write-a-Java-program-to-print-as-many-powers-of-2-as-the-user-requests

How to write a Java program to print as many powers of 2 as the user requests - Quora

Next, assuming that the powers of 2 must be integers . The easy way is to use BigDecimal, but it maxes out at [code ](2**2147483647) - 1[/code] - see: How to get biggest BigDecimal value . Beyo...

stackoverflow.com › questions › 5222966 › program-calculating-power-of-2

java - Program calculating power of 2 - Stack Overflow

2ⁿ == (1 << n); 0 <= n < 32

Just print nextPowerOf2 before you change it.

while (exponent<numPowersOf2)
{
    System.out.println(nextPowerOf2);

    nextPowerOf2=nextPowerOf2*2;
    exponent++;
}

w3resource.com › java-exercises › basic › java-basic-exercise-205.php

Java - Check an integer is power of 2 or not using O(1) time

Write a Java program to determine if a number is a power of 2 and count the number of right shifts needed to reduce it to 1.

dev.to › ggorantala › power-of-2-java-solution-b20

Power of Two, A Google Interview Question - Java Solution - DEV Community

March 4, 2022 - In binary, we go from right to left with powers of 2.

quora.com › How-do-I-find-if-a-number-is-power-of-2-for-Java-Assignment

How to find if a number is power of 2 for Java Assignment - Quora

Answer (1 of 3): import java.util.*; public class Power{ public static void main(String[] args) { //int num=0; int rem=0; Scanner sc=new Scanner(System.in); int num=sc.nextInt(); if(num==0) { System.out.println("no"); } while (num!=1) { rem=num%2; num=num/2; } if(num==1 && rem==0...

brainly.com › computers and technology › college › write a while loop that prints all powers of 2 that are less than a given number \( n \). for example, if \( n \) is 100, print: 1 2 4 8 16 32 64. ```java import java.util.scanner; public class powersoftwo { public static void main(string[] args) { scanner in = new scanner(system.in); system.out.print("n: "); int n = in.nextint(); int power = 1; while (power

[FREE] Write a while loop that prints all powers of 2 that are less than a given number n . For example, if n - brainly.com

A while loop to print all powers of 2 less than a given number n can be created by initializing a currentPower variable with 1, checking if it is less than n in the loop condition, printing it, then updating it by multiplying by 2. ... To create ...

quora.com › What-is-the-difference-between-math-pow-2-i-and-2-I-in-Java

What is the difference between math.pow(2,i) and 2^I in Java? - Quora

Answer (1 of 3): Math.pow function in Java performs the power operation of 2 to the power of i say for example, i is 3. Then 2 to the power 3 is 8 (2*2*2) ^ is a bitwise XOR operator.

baeldung.com › home › java › java numbers › using math.pow in java

Using Math.pow in Java | Baeldung

January 8, 2024 - Before looking at the example, let’s look at the method’s signature: public double pow(double a, double b) The method raises a to the power of b and returns the result as double. In other words, a is multiplied by itself b times. Let’s ...

geeksforgeeks.org › java › math-pow-method-in-java-with-example

Math pow() Method in Java with Example - GeeksforGeeks

March 28, 2025 - Example 1: This example demonstrates how to use the Math.pow() method in Java to calculate the power of a number (base raised to the exponent). ... // Java program to demonstrate working // of Math.pow() method // importing java.lang package ...

octoperf.com › blog › 2018 › 03 › 16 › java-math-pow

Java Math.pow Through Code Examples - OctoPerf

Usually, when you write the power of a number you use the following syntax: Using Math symbols: 2^5 = 2x2x2x2x2 = 32 Using Java Programming Language: Math.pow(2, 5)