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.
public class Solution { public int rangeBitwiseAnd(int m, int n) { if (m == 0) return 0; int powerOf2 = 1; while (m != n) { //if m!=n, current bit result is 0. m >>= 1; n >>= 1; powerOf2 <<= 1; } return m * powerOf2; } }
201. Bitwise AND of Numbers Range
原文：http://www.cnblogs.com/neweracoding/p/5722316.html