leetcode-190-颠倒二进制位

class Solution:
    # @param n, an integer
    # @return an integer
    def reverseBits(self, n):
        return int(bin(n)[2:].zfill(32)[::-1],2)

class Solution:
    # @param n, an integer
    # @return an integer
    def reverseBits(self, n):
        res = 0 
        count = 32
        while count: 
            res <<= 1 # 取出 n 的最低位数加到 res 中 
            res += n&1 
            n >>= 1 
            count -= 1 
        return int(bin(res), 2)