leetcode------Bitwise AND of Numbers Range

标题：	Bitwise AND of Numbers Range
通过率：	25.7%
难度：	中等

Given a range [m, n] where 0 <= m <= n <= 2147483647, return the bitwise AND of all numbers in this range, inclusive.

For example, given the range [5, 7], you should return 4.

就是将区间内的所有数字按位与的结果，如果按照每个数字的去与，那么是超时的，直接贴出代码把。。这个只能生办硬套：

 1 class Solution:

 2     # @param m, an integer

 3     # @param n, an integer

 4     # @return an integer

 5     def rangeBitwiseAnd(self, m, n):

 6         offset=0

 7         while m !=n :

 8             m>>=1

 9             n>>=1

10             offset+=1

11         return m<<offset