Bitwise AND of Numbers Range

public class Solution {
    public int rangeBitwiseAnd(int m, int n) {
        if( m>n || m<=0 || n<=0) return 0;
        if(m == n)  return m;
        if(m == n-1)    return m&n;
        int mid = (m+n)/2;
        return  mid & rangeBitwiseAnd(m,mid-1) & rangeBitwiseAnd(mid+1,n); 
    }
}

public class Solution {
    public int rangeBitwiseAnd(int m, int n) {
        if(m == 0){
            return 0;
        }
        int moveFactor = 1;
        while(m != n){
            m >>= 1;
            n >>= 1;
            moveFactor <<= 1;
        }
        return m * moveFactor;
    }
}