Return the bitwise AND of all numbers in the range

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

Example 1:

Input: m = 5, n = 7

Output: 4

class Solution1(object):
    def rangeBitwiseAnd(self, m, n) -> int:
        """
        :type m: int
        :type n: int
        :rtype: int
        """
        while m < n:
            n &= n - 1
        return n

s = Solution1()
m = 5
n = 7
assert s.rangeBitwiseAnd(m, n) == 4

class Solution2(object):
    def rangeBitwiseAnd(self, m, n) -> int:
        """
        :type m: int
        :type n: int
        :rtype: int
        """
        i, diff = 0, n - m
        while diff:
            diff >>= 1
            i += 1
        return n & m >> i << i

s = Solution2()
m = 5
n = 7
assert s.rangeBitwiseAnd(m, n) == 4

See also:

https://leetcode.com/problems/bitwise-and-of-numbers-range

https://www.lintcode.com/problem/bitwise-and-of-numbers-range