Power of Two — LeetCode 231 Python Solution

EasyBit ManipulationRecursionMath
Problem
#231
Reading time
2 min

The problem

Given an integer n, return true if it is a power of two. Otherwise, return false.

Example

Input
n = 1
Output
true
Explanation
20 = 1

Python solution

Python
class Solution:
    def isPowerOfTwo(self, n: int) -> bool:
        return n > 0 and (n & (n - 1)) == 0

Complexity

MeasureComplexity
TimeO(1)
SpaceO(1) auxiliary

Pattern: Bit Manipulation

Use XOR, masks and the low-bit trick to replace whole data structures with an integer. LeetCode 231. Power of Two is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Bit Manipulation.

The bit manipulation guide has the Python template for the pattern and the 194 LeetCode problems that use it.

Related problems

Frequently asked questions

How hard is LeetCode 231. Power of Two?
LeetCode 231. Power of Two is rated Easy on LeetCode.
What is the time complexity of LeetCode 231. Power of Two?
The Python solution on this page runs in O(1).
What is the space complexity of LeetCode 231. Power of Two?
The Python solution on this page uses O(1) auxiliary space.
What topics does LeetCode 231. Power of Two cover?
LeetCode 231. Power of Two is tagged Bit Manipulation, Recursion and Math on LeetCode.

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