leetcode之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.

Credits:
Special thanks to @ts for adding this problem and creating all test cases.

主要思想是：利用了与操作依次对数进行递减1，统计每次相与后1的数目。

class Solution {public:    int hammingWeight(int n) {     int count=0;;//memset(a,0,size(int)*32); while(n){n=n&(n-1);count++;}return count;    }};