Power of Four — LeetCode 342 Python Solution

EasyBit ManipulationRecursionMath
Problem
#342
Reading time
2 min

The problem

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

Example

Input
n = 16
Output
true

Python solution

Python
class Solution:
    def isPowerOfFour(self, n: int) -> bool:
        return n > 0 and (n & (n - 1)) == 0 and (n & 0xAAAAAAAA) == 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 342. Power of Four 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 342. Power of Four?
LeetCode 342. Power of Four is rated Easy on LeetCode.
What is the time complexity of LeetCode 342. Power of Four?
The Python solution on this page runs in O(1).
What is the space complexity of LeetCode 342. Power of Four?
The Python solution on this page uses O(1) auxiliary space.
What topics does LeetCode 342. Power of Four cover?
LeetCode 342. Power of Four is tagged Bit Manipulation, Recursion and Math on LeetCode.

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