LeetCode-Power of Three
Given an integer, write a function to determine if it is a power of three. Follow up: Could you do it without using any loop / recursion?
public class Solution { private static final double epsilon=10e-15; public boolean isPowerOfThree(int n) { if(n<=0){return false;} if(n==1){return true;} double res=Math.log(n)/Math.log(3); return Math.abs(res - Math.round(res)) < epsilon; } }
posted on 2016-07-19 03:05 IncredibleThings 阅读(126) 评论(0) 编辑 收藏 举报