0342. Power of Four

https://leetcode.com/problems/power-of-four

Description

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

An integer n is a power of four, if there exists an integer x such that n == 4x.

Example 1:

**Input:** n = 16
**Output:** true

Example 2:

**Input:** n = 5
**Output:** false

Example 3:

**Input:** n = 1
**Output:** true

Constraints:

• -231 <= n <= 231 - 1

Follow up: Could you solve it without loops/recursion?

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