leetcode刷题笔记(Golang)--342. Power of Four

342. Power of Four

Given an integer (signed 32 bits), write a function to check whether it is a power of 4.

Example 1:

Input: 16
Output: true
Example 2:

Input: 5
Output: false
Follow up: Could you solve it without loops/recursion?

func isPowerOfFour(num int) bool {
	if num == 0 {
		return false
	}
	if num == 1 {
		return true
	}
	if num%4 == 0 {
		return isPowerOfFour(num / 4)
	} else {
		return false
	}
}