leetcode:Bitwise AND of Numbers Range

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.

Credits:
Special thanks to @amrsaqr for adding this problem and creating all test cases.

class Solution {public:    int rangeBitwiseAnd(int m, int n) {        int p = 0;        while (m != n)        {            m = m>>1;            n = n>>1;            p++;        }                return m<<p;    }};