Number of 1 Bits

题目地址：
https://leetcode.com/problems/number-of-1-bits/#/description

题目：

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.

解题思路：
这道题主要就是要用比特操作。

代码：

public static int hammingWeight(int n) {
    int count = 0;
    for(int i = 0; i <= 31; i++){
        count += ((n & 1) == 1) ? 1 : 0;
        n >>= 1;
    }
    return count;
}