【[LeetCode] 342. Power of Four 4的次方数】的更多相关文章

[LeetCode] 342. Power of Four 4的次方数

Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example:Given num = 16, return true. Given num = 5, return false. Follow up: Could you solve it without loops/recursion? Credits:Special thanks to @yukuairoyfor…

[LeetCode] 231. Power of Two 2的次方数

Given an integer, write a function to determine if it is a power of two. Example 1: Input: 1 Output: true Example 2: Input: 16 Output: true Example 3: Input: 218 Output: false 给一个整数,写一个函数来判断它是否为2的次方数. 利用计算机用的是二进制的特点,用位操作,此题变得很简单. 2的n次方的特点是:二进制表示中最高位是…

[LeetCode] 326. Power of Three 3的次方数

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? Credits:Special thanks to @dietpepsi for adding this problem and creating all test cases. 给一个整数,写一个函数来判断此数是不是3的次方…

LeetCode 342. Power of Four （4的次方）

Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example:Given num = 16, return true. Given num = 5, return false. Follow up: Could you solve it without loops/recursion? 题目标签:Bit Manipulation 这道题目让我们判断一个数字是不是4的…

LeetCode 342. Power of Four

Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example:Given num = 16, return true. Given num = 5, return false. Follow up: Could you solve it without loops/recursion? 先说明用循环: 如下 class Solution { public: bool…

Leetcode 342 Power of Four 数论

题意:判断一个数是不是4的幂数,和Power of two类似. 先判断num是否大于0,再判断num是否能开根号,最后判断num开根号后的数是否是2^15的约数. 提示:4的幂数开根号就是2的幂数. 注意:判断一个双精度数a是否是0,请用fabs(a)<一个极小的数,如本题中用的是1e-9. class Solution { public: bool isPowerOfFour(int num) { ) && (fabs(( ) && ((<<) % (…

Python [Leetcode 342]Power of Four

题目描述: Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example:Given num = 16, return true. Given num = 5, return false. 解题思路: 位操作. 首先判断是不是只有一位数字为1,其余为0 然后判断为1的位置是不是奇数位 代码如下: class Solution(object): def isPower…

[LeetCode] 342. Power of Four（位操作）

传送门 Description Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example:Given num = 16, return true. Given num = 5, return false. Follow up: Could you solve it without loops/recursion? 思路 题意:不使用循环和递归,求一个数是否是4的…

[LeetCode] 231 Power of Two && 326 Power of Three && 342 Power of Four

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…

[LeetCode] Power of Four 判断4的次方数

Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example: Given num = 16, return true. Given num = 5, return false. Follow up: Could you solve it without loops/recursion? Credits:Special thanks to @yukuairoy fo…