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:数二进制1的个数
方法一:
class Solution(object):
def hammingWeight(self, n):
"""
:type n: int
:rtype: int
"""
return bin(n).count('1')
方法二:移位+按位与操作
class Solution(object):
def hammingWeight(self, n):
"""
:type n: int
:rtype: int
"""
count = 0
while n:
count += n&1
n >>= 1
return count