LeetCode题解：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.

题意：求二进制字符串中1的个数

解决思路：调API，或不断右移一位计数

代码：

public class Solution {
    public int hammingWeight(int n) {
        return Integer.bitCount(n);
    }
}