> For the complete documentation index, see [llms.txt](https://liuyang89116.gitbook.io/my-leetcode-book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://liuyang89116.gitbook.io/my-leetcode-book/post_chapter_2_math/problem-342-power-of-four/problem-326-power-of-three.md).

# Problem 326: Power of Three

> <https://leetcode.com/problems/power-of-three/#/description>

## 思路

* $$n = 3 ^ m$$ 等价于 $$log(n) = m \* log(3)$$

```java
public class Solution {
    public boolean isPowerOfThree(int n) {
        return (Math.log10(n) / Math.log10(3)) % 1 == 0; 
    }
}
```

```java
public class Solution {
    public boolean isPowerOfThree(int n) {
        if (n > 1) {
            while (n % 3 == 0) n /= 3;
        }

        return n == 1;
    }
}
```