LeetCode 191. Number of 1 Bits(java)

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.

解法：bit manipulation, 每次右移一位，然后and1来求这一位是否是1。

public int hammingWeight(int n) {
        int result = 0;
        for (int i = 0; i < 32; i++) {
            int tag = n & 1;
            if (tag == 1) {
                result += 1;
            }
            n = n >> 1;
        }
        return result;
    }