Number of 1 Bits

Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as theHamming weight).

For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011, so the function should return 3.

题目解析：输出一个数字二进制中1的个数

解法解析：有个小技巧而已 n&（n-1）每次都能消灭一个1，比较简单，直接上AC代码

public int hammingWeight(int n) {if(n==0)return 0;int count = 0;while(n!=0){n = n&(n-1);count++;}return count;}