728. Self Dividing Numbers 笔记

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.

就是找能整除自己左右位的数字的数。分别把每一位取出来判断，是0或者不能整除直接返回false。

class Solution {
public:
    vector<int> selfDividingNumbers(int left, int right) {
        vector<int> res;
        for(int i = left; i <= right; i++)
        {
            if(isSelfDividingNumbers(i))
                res.push_back(i);
        }
        return res;
    }
    bool isSelfDividingNumbers(int i)
    {
        int num = i;
        while(num != 0)
        {
            int j = num % 10;// 最后一位
            num = num / 10;
            if(j == 0)
                return false;
            else if(i % j != 0)
                return false;
        }
        return true;
    }
};