leetcode:191 Number of 1 Bits－每日编程第十三题

Number of 1 Bits

Total Accepted: 63943 Total Submissions: 169155 Difficulty: Easy

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：

1).n&1判断n是最后一位是否为1,是的话，num+1.之后再右移一位。

2).重复1). 直到n变为0

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