无聊的刷题笔记

Number Of 1 Bits

LeetCode 191

Write a function that takes an unsigned integer and returns the number of ‘1’ bits it has (also known as the Hamming weight).

Example 1:

Input: 11
Output: 3
Explanation: Integer 11 has binary representation 00000000000000000000000000001011

Example 2:

Input: 128
Output: 1
Explanation: Integer 128 has binary representation 00000000000000000000000010000000
class Solution(object):
def hammingWeight(self, n):
"""
:type n: int
:rtype: int
"""
ans = 0
while n!=0:
if n&1:
ans+=1
n = n>>1
return ans