题目链接

按位查找

class Solution:
    def hammingWeight(self, n: int) -> int:
        ans = 0
        while n:
            if n & 1 == 1:
                ans += 1
            n >>= 1
        return ans

利用二进制特性

class Solution:
    def hammingWeight(self, n: int) -> int:
        ans = 0
        while n:
            n = n & (n-1)
            ans += 1
        return ans