191. Number of 1 Bits

题目：Number of 1 Bits

原题链接：https://leetcode.com/problems/number-of-1-bits/ 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.

编写一个算法，返回一个32位无符号整数的二进制位中1的个数。

由于确定了是一个32位的数，所以只要从最低位到最高位，逐位判断是不是 1 就行。

代码如下：

class Solution { public: int hammingWeight(uint32_t n) { int ans = 0; for (int i = 0; i < 32; ++i) { if(n & 1) ans++; n = n >> 1; } return ans; } };