Question
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
.
Example 1:
Input: n = 1 Output: true Explanation: 20 = 1
Example 2:
Input: n = 16 Output: true Explanation: 24 = 16
Example 3:
Input: n = 3 Output: false
Constraints:
-231 <= n <= 231 - 1
Follow up: Could you solve it without loops/recursion?
Python Solution
class Solution: def isPowerOfTwo(self, n: int) -> bool: if n<=0: return False while n>0: if n==1: return True elif n%2==0: n/=2 else: return False