# [LeetCode]#231. Power of Two

**Environment: Python 3.7**

**Key technique:** Recursion

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

**Analysis:**

Use recursion method to find value is power of two or not.

**Solution:**

`class Solution:`

def isPowerOfTwo(self, n):

if n == 1:

return True

elif n==0:

return False

elif n % 2 != 0:

return False

else:

return self.isPowerOfTwo(n/2)

**Submitted result:**

**Reference:**

https://leetcode.com/problems/power-of-two/discuss/546332/Python-Recursion