LeetCode 191. Number of 1 bits (位1的数量)

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.


题目标签:Bit Manipulation

  这题给我们一个integer,让我们找到bits中1的个数,利用 & 1 判断bit是不是1,然后利用 >> 来移动bits。

Java Solution:

Runtime beats 16.07%

完成日期:06/26/2017

关键词:Bit Manipulation

关键点:用 & 拿到bit, 用 >> 来移动bits

 public class Solution
{
// you need to treat n as an unsigned value
public int hammingWeight(int n)
{
int res = 0; for(int i=0; i<32; i++)
{
if((n & 1) == 1) // meaning the most right bit is 1
res++; n = n >> 1; // shift to right 1 bit
} return res;
}
}

参考资料: N/A

LeetCode 算法题目列表 - LeetCode Algorithms Questions List

上一篇:tcpdump参数及使用介绍(转)


下一篇:png透明图片