leetcode 326. Power of Three(不用循环或递归) 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? 题意是判断一个数是否是3的幂,最简单的也最容易想到的办法就是递归判断,或者循环除. 有另一种方法就是,求log以3为底n的对数.类似 如果n=9,则…

326. 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? 思路:看这个数取以3为底的对数结果是否为整数,C++中只有自然对数函数log()和以10为底的对数函数log10(),所以要借助换底公式.此处用自然对数会有精度问题,用以10为底的对数…

这三道题目都是一个意思,就是判断一个数是否为2/3/4的幂,这几道题里面有通用的方法,也有各自的方法,我会分别讨论讨论. 原题地址:231 Power of Two:https://leetcode.com/problems/power-of-two/description/ 326 Power of Three:https://leetcode.com/problems/power-of-three/description/ 342 Power of Four :https://leetcod…

326. Power of Three Question Total Accepted: 1159 Total Submissions: 3275 Difficulty: Easy 推断给定整数是否是3的某次方. 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? 完毕此题.…

Problem: Given an integer, write a function to determine if it is a power of three. Could you do it without using any loop / recursion? Summary: 用非循环/递归的方法判断数n是否为3的整数幂. Analysis: 1. 循环:将n逐次除以3,判断是否为3的整数幂. class Solution { public: bool isPowerOfThree(…

/* 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 PowerOfThree { private static final double EX=10e-15; public static void main(String[] args) {…

题目描述: 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? 解题思路: 对给定的数求以3为底的对数,然后再将结果用于3的次幂,看是否与原来的数相同. 代码如下: public class Solution { public boolean isPowerOfThree(in…

一天一道LeetCode 本系列文章已全部上传至我的github,地址:ZeeCoder's Github 欢迎大家关注我的新浪微博,我的新浪微博 欢迎转载,转载请注明出处 (一)题目 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? (二)解题 题目大意:判断一个是不是3…

翻译 给定一个整型数,写一个函数决定它是否是3的幂(翻译可能不太合适-- 跟进: 你能否够不用不论什么循环或递归来完毕. 原文 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? 分析 题意我事实上不是满懂,比方说12究竟可不能够呢?还是说仅仅有:3.9.27.81这样的才行…

原题: 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? 这个题目本身没有任何难度,也是easy等级,但是题目要求不能使用循环和迭代,解法如下: import math class Solution(object): def isPowerOfThree(self, n):…