728. Self Dividing Numbers

728. Self Dividing Numbers (Easy)

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 = 22
Output: [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.

Solution 1.

// OJ: https://leetcode.com/problems/self-dividing-numbers/
// Author: github.com/lzl124631x
// Time: O(ND) where N = right - left + 1, D = digit count of right.
// Space: O(1)
class Solution {
private:
    bool isSelfDividing(int n) {
        int m = n;
        while (m) {
            int d = m % 10;
            if (!d || n % d != 0) return false;
            m /= 10;
        }
        return true;
    }
public:
    vector<int> selfDividingNumbers(int left, int right) {
        vector<int> ans;
        for (int i = left; i <= right; ++i) {
            if (isSelfDividing(i)) ans.push_back(i);
        }
        return ans;
    }
};