leetcode Reverse Bits---ポイント

https://leetcode.com/problems/reverse-bits/
参照http://bookshadow.com/weblog/2015/03/08/leetcode-reverse-bits/

class Solution(object):
    def reverseBits(self, n):
        """ :type n: int :rtype: int """
        ans = 0
        for i in range(32):
            ans <<= 1#          n     ，     
            ans |= n & 1 #           ，      ans      
            n >>= 1#    
        return ans