Given an integer, determine whether it is a power of four.
Example 1:
Input: n = 16
Output: true
Explanation: 16 = 4^2
Example 2:
Input: n = 5
Output: false
Example 3:
Input: n = 1
Output: true
Explanation: 4^0 = 1
bitsTime: O(1)Space: O(1)Frequency: 3
Given an integer, determine whether it is a power of four.
Example 1:
Input: n = 16
Output: true
Explanation: 16 = 4^2
Example 2:
Input: n = 5
Output: false
Example 3:
Input: n = 1
Output: true
Explanation: 4^0 = 1
bit-manipulation