22 Self Dividing Numbers

题目

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.

分析

题意： 如果一个数，能够被它的所有位上的数整除，这个数被称为自除数（这个数任意位上肯定不包含0） 给定一个区间[left,right]，返回在这个区间内的所有自除数。

算法：穷举 挨个遍历数字，然后通过除以10再取余10的方式拿到每一位进行验证

解答

class Solution {
    public List<Integer> selfDividingNumbers(int left, int right) {
        List<Integer> list = new ArrayList<>();
        for (int i = left; i <= right; i++) {
            int j = i;
            for (; j > 0; j /= 10) {
                if ((j % 10 == 0) || (i % (j % 10) != 0)) break;
            }
            if (j == 0) list.add(i); 
        }
        return list;
    }
}