342. Power of Four
Easy
Given an integer (signed 32 bits), write a function to check whether it is a power of 4.
Example 1:
Input: 16
Output: true
Example 2:
Input: 5
Output: false
Follow up: Could you solve it without loops/recursion?
package leetcode.easy; public class PowerOfFour { public boolean isPowerOfFour(int num) { if (num < 1) { return false; } while (num % 4 == 0) { num /= 4; } return num == 1; } @org.junit.Test public void test() { System.out.println(isPowerOfFour(16)); System.out.println(isPowerOfFour(5)); } }