[191]Number of 1 Bits

【题目描述】

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.

【思路】

采用移位和逻辑运算做的，代码比以前整洁很多

【代码】

class Solution {
public:
    int hammingWeight(uint32_t n) {
        int ans=0;
        for(int i=0;i<=31;i++,n>>=1){
            if(n&1) ans++;
        }
        return ans;
    }
};