leetcode 191 Number of 1 Bits(位运算)

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.

 

题解：很简单，一位一位的和1做"与"运算就好。

class Solution {
public:
    int hammingWeight(uint32_t n) {
        int ans=0;
        while(n>0){
            ans+=((n&1)==0?0:1);
            n>>=1;
        }
        return ans;
    }
};