power-of-three

java

python

python3

mysql

mssql

oraclesql

csharp

javascript

typescript

bash

swift

kotlin

dart

golang

ruby

scala

rust

racket

erlang

elixir

pythondata

postgresql

cangjie

Algorithms

Given an integer <code>n</code>, return <code>true</code> if it is a power of three. Otherwise, return <code>false</code>.

An integer <code>n</code> is a power of three, if there exists an integer <code>x</code> such that <code>n == 3x</code>.

&nbsp;
Example 1:

<pre>
Input: n = 27
Output: true
Explanation: 27 = 33
</pre>

Example 2:

<pre>
Input: n = 0
Output: false
Explanation: There is no x where 3x = 0.
</pre>

Example 3:

<pre>
Input: n = -1
Output: false
Explanation: There is no x where 3x = (-1).
</pre>

&nbsp;
Constraints:

<ul>
	<li><code>-231 &lt;= n &lt;= 231 - 1</code></li>
</ul>

&nbsp;
Follow up: Could you solve it without loops/recursion?

isPowerOfThree

Power of Three

Power of Two

power-of-two

2 的幂

Power of Four

power-of-four

4的幂

Check if Number is a Sum of Powers of Three

check-if-number-is-a-sum-of-powers-of-three

判断一个数字是否可以表示成三的幂的和

Recursion

Math

给定一个整数，写一个函数来判断它是否是 3&nbsp;的幂次方。如果是，返回 <code>true</code> ；否则，返回 <code>false</code> 。

整数 <code>n</code> 是 3 的幂次方需满足：存在整数 <code>x</code> 使得 <code>n == 3x</code>

&nbsp;

示例 1：

<pre>
输入：n = 27
输出：true
</pre>

示例 2：

<pre>
输入：n = 0
输出：false
</pre>

示例 3：

<pre>
输入：n = 9
输出：true
</pre>

示例 4：

<pre>
输入：n = 45
输出：false
</pre>

&nbsp;

提示：

<ul>
	<li><code>-231 &lt;= n &lt;= 231 - 1</code></li>
</ul>

&nbsp;

进阶：你能不使用循环或者递归来完成本题吗？