Description
https://leetcode.com/problems/power-of-three/
Given an integer, write a function to determine if it is a power of three.
Example 1:
Input: 27 Output: true
Example 2:
Input: 0 Output: false
Example 3:
Input: 9 Output: true
Example 4:
Input: 45 Output: false
Follow up:
Could you do it without using any loop / recursion?
Explanation
keep dividing by three to see if the number is a power of three
Python Solution
class Solution:
def isPowerOfThree(self, n: int) -> bool:
while n > 1:
if n % 3 != 0:
return False
n = n // 3
return n == 1- Time complexity: O(N).
- Space complexity: O(1).
public boolean isPowerOfThree2(int n) {
if(n == 0)
return false;
while (n % 3 == 0){
n = n / 3;
}
if (n == 1)
return true;
else
return false;
}
public boolean isPowerOfThree(int n) {
if(n==0) return false;
while(n!=1){
if(n%3 !=0) return false;
n = n/3;
}
return true;
}