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Java-based LeetCode algorithm problem solutions, regularly updated

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package g0301_0400.s0342_power_of_four;

// #Easy #Math #Bit_Manipulation #Recursion #2022_07_10_Time_1_ms_(100.00%)_Space_41.2_MB_(55.90%)

/**
 * 342 - Power of Four\.
 *
 * Easy
 *
 * 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 == 4^x.
 *
 * **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?
**/
public class Solution {
    public boolean isPowerOfFour(int n) {
        while (n >= 4) {
            if (n % 4 != 0) {
                return false;
            }
            n = n / 4;
        }
        return n == 1;
    }
}