728. Self Dividing Numbers

A self-dividing number is a number that is divisible by every digit it contains.

For example, 128 is a self-dividing number because 128 % 1 == 0, 128 % 2 == 0, and 128 % 8 == 0.

Also, a self-dividing number is not allowed to contain the digit zero.

Given a lower and upper number bound, output a list of every possible self dividing number, including the bounds if possible.

Example 1:

Input: left = 1, right = 22Output: [1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 15, 22]

Note:

The boundaries of each input argument are 1 <= left <= right <= 10000.

自己写的答案：

public class Solution {
     private static bool return_zhi(int a)
        {
            int index = 1;
            int d = a;
            while (a != 0)
            {
                int tmp = a % (10 * index);
                a = a - tmp;
                index *= 10;
                while (tmp != 0 && tmp % 10 == 0)
                {
                    tmp = tmp / 10;
                }
                if (tmp == 0 || d % tmp != 0)
                {
                    return false;
                }
            }
            return true; 
        }
    public IList<int> SelfDividingNumbers(int left, int right) {
        IList<int> il=new List<int>();
        for(int i=left;i<right+1;i++)
        {
            if(return_zhi(i))
            {
                il.Add(i);
            }
        }
        return il;        
    }
}