# Leetcode Algorithms

231. Power of Two

Given an integer, write a function to determine if it is a power of two.

**Example 1:**

**Input:** 1

**Output:** true

**Explanation: **20 = 1

**Example 2:**

**Input:** 16

**Output:** true

**Explanation: **24 = 16

**Example 3:**

**Input:** 218

**Output:** false

Logic:

Power of 2 means only 1 bit of n is 1. Hence, we can use bitwise operation: (n&(n-1)) == 1 to test if n is the power of 2

Solution:

`class Solution:`

def isPowerOfTwo(self, n:int) -> bool:

if n <= 0:

return False

elif (n&(n - 1)) == 0:

return True