leetcode201.数字范围按位与

找到公共前缀部分，然后后面的部分全0

class Solution {
    public int rangeBitwiseAnd(int left, int right) {
        int offset = 0;
        while (left != right) {
            offset++;
            left = left >> 1;
            right = right >> 1;
        }
        return right << offset;
    }
}