English
342. Power of Four
Problem Statement
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?
Solution:
rs
impl Solution {
pub fn is_power_of_four(n: i32) -> bool {
if n <= 0 {
return false;
}
let mut n = n;
while n % 4 == 0 {
n /= 4;
}
n == 1
}
}
...