Leetcode16: Number of 1 Bits
来源:互联网 发布:如何ping mac地址 编辑:程序博客网 时间:2024/06/03 16:45
Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).
For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011
, so the function should return 3.
class Solution {public: int hammingWeight(uint32_t n) { int k = 0; while(n) { k += (n & 0x1) > 0 ? 1 : 0; //(n % 2) > 0 ? 1 : 0; n >>= 1; //n /= 2; } return k; }};
下面这种方法更为简单。假设n= 1111000111000 那 n-1 = 1111000110111, (n-1) & n = 1111000110000,刚好把最后一个1给干掉了。也就是说, (n-1)&n 刚好会从最后一位开始,每次会干掉一个1.这样速度就比上面哪种方法快了。有几个1,就执行几次。(学渣表示震惊!= =)
class Solution {public: int hammingWeight(uint32_t n) { int k = 0; while(n != 0) { n = n & (n-1); k++; } return k; }};
1 0
- Leetcode16: Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- Number of 1 Bits
- 双向链表list
- jqwidgets-tab
- OpenGLES demo - 17. es30和es31新特性及改变
- 天声人語 20150423
- POJ 2051 Argus(优先队列)
- Leetcode16: Number of 1 Bits
- 某ssh后门试用
- Android 5.0 Design 沉浸式状态栏
- Professor Q's Software Java版本
- showModalDialog简单案例及使用
- 欢迎使用CSDN-markdown编辑器
- wamp下 403 Forbidden问题轻松解决
- 一个适配器公用,多个布局文件同用一个适配器
- 最小二乘法建模