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.…

#-*- coding: UTF-8 -*- class Solution(object):    def isPowerOfThree(self, n):        if n<=0:            return False        while True:            if n==3 or n==1:                return True            tuple=divmod(n,3)            if tuple[1]!=0:  …

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…

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 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…

博客搬至blog.csgrandeur.com,cnblogs不再更新. 新的题解会更新在新博客:http://blog.csgrandeur.com/2014/01/15/LeetCode-OJ-Solution/ ———————————————————————————————————————— ———————————————————————————————————————— LeetCode OJ 题解 LeetCode OJ is a platform for preparing tech…

Problem Link: http://oj.leetcode.com/problems/interleaving-string/ Given s1, s2, s3, find whether s3 is formed by the interleaving of s1 and s2. For example, Given: s1 = "aabcc", s2 = "dbbca", When s3 = "aadbbcbcac", return t…

Problem link: http://oj.leetcode.com/problems/reverse-words-in-a-string/ Given an input string, reverse the string word by word. For example, Given s = "the sky is blue", return "blue is sky the". LeetCode OJ supports Python now! The s…

一直没有系统地学习过算法,不过算法确实是需要系统学习的.大二上学期,在导师的建议下开始学习数据结构,零零散散的一学期,有了链表.栈.队列.树.图等的概念.又看了下那几个经典的算法——贪心算法.分治算法.动态规划以及回溯算法.不过,都是知其一不知其二的一知半解.到最后,发现学到了一堆的一知半解,在学校课程开这门课时,却又是不得不再学一遍.学一样东西,又不全心全意地主动去把它学好,到最后只是花费了时间,却没真真学到东西.所以,不求学识有多广,但求所学的都精. 一个偶然的机会,让我在网上找到了一本社区…

Serialization is the process of converting a data structure or object into a sequence of bits so that it can be stored in a file or memory buffer, or transmitted across a network connection link to be reconstructed later in the same or another comput…