LeetCode 728. Self Dividing Numbers

LeetCode 728. Self Dividing Numbers

Description

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.

class Solution {    public List<Integer> selfDividingNumbers(int left, int right) {        List<Integer> ret = new ArrayList<>();        for (int n = left; n <= right; ++n) {            if (selfDividing(n)) {                ret.add(n);            }        }        return ret;    }    public boolean selfDividing(int n) {        for (char c: String.valueOf(n).toCharArray()) {            if (c == '0' || (n % (c - '0') > 0))                return false;        }        return true;    }}

Complexity Analysis

Time Complexity: O(D), where D is the number of integers in the range [L,R], and assuming log(R) is bounded. (In general, the complexity would be O(DlogR).)

Space Complexity: O(D), the length of the answer.