LeetCode191-位1的个数

转字符串计算长度

public int hammingWeight1(int n) {
       return Integer.toBinaryString(n).replace("0","").length();
   }

位运算符

//位运算
    public static int hammingWeight2(int n) {
        int count = 0;
        while (n != 0) {
            count += n & 1;
            n >>>= 1;
        }
        return count;
    }