LWC 59：728. Self Dividing Numbers

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发布于 2018-01-02 10:45:33

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发布于 2018-01-02 10:45:33

文章被收录于专栏：机器学习入门

LWC 59：728. Self Dividing Numbers

传送门：728. Self Dividing Numbers

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:

The boundaries of each input argument are 1 <= left <= right <= 10000.

思路：非常直观，对每个num，进行拆分判断，合法加入集合，不合法忽略。

一版本：

    public List<Integer> selfDividingNumbers(int left, int right) {
        List<Integer> ans = new ArrayList<>();
        for (int i = left; i <= right; ++i) {
            if (valid(i)) {
                ans.add(i);
            }
        }
        return ans;
    }

    boolean valid(int num) {
        String value = Integer.toString(num);
        for (char c : value.toCharArray()) {
            if (c == '0') return false;
            else {
                if (num % (c - '0') != 0) return false;
            }
        }
        return true;
    }

二版本：

    public List<Integer> selfDividingNumbers(int left, int right) {
        List<Integer> ans = new ArrayList<>();
        for (int i = left; i <= right; ++i) {
            if (valid(i)) {
                ans.add(i);
            }
        }
        return ans;
    }

    boolean valid (int num) {
        int n = num;
        while (num != 0) {
            int c = num % 10;
            if (c == 0) return false;
            else {
                if (n % c != 0) return false;
            }
            num /= 10;
        }
        return true;
    }

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原始发表：2017-11-19 ，如有侵权请联系 cloudcommunity@tencent.com 删除

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