728. Self Dividing Numbers

• Difficulty: Easy

• Topics: Math

• Similar Questions:

  • Perfect Number

Problem:

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:

Solutions:

class Solution {
public:
    vector<int> selfDividingNumbers(int left, int right) {
        vector<int> ret;
        for (int i = left; i <= right; ++i) {
            if (isSelfDivided(i)) {
                ret.push_back(i);
            }
        }

        return ret;
    }

private:
    bool isSelfDivided(int num) {
        int clone = num;
        while (clone > 0) {
            int digit = clone % 10;
            if (digit == 0) return false;
            clone /= 10;
            if (num % digit != 0)   return false;
        }

        return true;
    }
};