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Java-based LeetCode algorithm problem solutions, regularly updated

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package g0301_0400.s0326_power_of_three;

// #Easy #Top_Interview_Questions #Math #Recursion
// #2022_07_09_Time_18_ms_(85.35%)_Space_47.9_MB_(14.68%)

/**
 * 326 - Power of Three\.
 *
 * Easy
 *
 * Given an integer `n`, return _`true` if it is a power of three. Otherwise, return `false`_.
 *
 * An integer `n` is a power of three, if there exists an integer `x` such that n == 3^x.
 *
 * **Example 1:**
 *
 * **Input:** n = 27
 *
 * **Output:** true 
 *
 * **Example 2:**
 *
 * **Input:** n = 0
 *
 * **Output:** false 
 *
 * **Example 3:**
 *
 * **Input:** n = 9
 *
 * **Output:** true 
 *
 * **Constraints:**
 *
 * *   -2³¹ <= n <= 2³¹ - 1
 *
 * **Follow up:** Could you solve it without loops/recursion?
**/
public class Solution {
    // regular method that has a loop
    public boolean isPowerOfThree(int n) {
        if (n < 3 && n != 1) {
            return false;
        }
        while (n != 1) {
            if (n % 3 != 0) {
                return false;
            }
            n /= 3;
        }
        return true;
    }
}