LeetCode 342】的更多相关文章

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…
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…
342. 4的幂 给定一个整数 (32 位有符号整数),请编写一个函数来判断它是否是 4 的幂次方. 示例 1: 输入: 16 输出: true 示例 2: 输入: 5 输出: false 进阶: 你能不使用循环或者递归来完成本题吗? class Solution { public boolean isPowerOfFour(int num) { int x = 0x55555555; return (num > 0)&&((num&(num-1))==0)&((nu…
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…
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(( ) && ((<<) % (…
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…
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? /************************…
描述 给定一个整数 (32 位有符号整数),请编写一个函数来判断它是否是 4 的幂次方. 示例 1: 输入: 16输出: true示例 2: 输入: 5输出: false 进阶:你能不使用循环或者递归来完成本题吗? 解析 32位数如果是4的幂,那么只有奇数位有且只有一个1,偶数位都是0.判断条件为: 1. 与0xaaaaaaaa做与运算结果为0.(a=1010) 2. num & (num - 1) == 0,说明只有1位的  1 代码 public boolean isPowerOfFour(…
1. 题目描述 给定一个整数 (32 位有符号整数),请编写一个函数来判断它是否是 4 的幂次方. 示例 1: 输入: 16输出: true示例 2: 输入: 5输出: false 2. 思路 参考:https://blog.csdn.net/weixin_40163242/article/details/97396427 . 3.代码 class Solution: def isPowerOfFour(self, num: int) -> bool: temp = num & (num -…
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…