LeetCode_342. Power of Four

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));
	}
}

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转载自www.cnblogs.com/denggelin/p/11813336.html