LeetCode_231. Power of Two

Posted 2021-03-24 邓戈麟

 

231. Power of Two

Easy

Given an integer, write a function to determine if it is a power of two.

Example 1:

Input: 1
Output: true 
Explanation: 20 = 1

Example 2:

Input: 16
Output: true
Explanation: 24 = 16

Example 3:

Input: 218
Output: false

 

package leetcode.easy;

public class PowerOfTwo {
	public boolean isPowerOfTwo(int n) {
		if (n <= 0) {
			return false;
		}
		if (n == 1) {
			return true;
		}
		if ((n & (n - 1)) == 0) {
			return true;
		}
		return false;
	}

	@org.junit.Test
	public void test() {
		System.out.println(isPowerOfTwo(1));
		System.out.println(isPowerOfTwo(16));
		System.out.println(isPowerOfTwo(218));
	}
}