LWC 59:728. Self Dividing Numbers

2018-01-02 10:45:33 浏览数 (1)

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:

代码语言:javascript复制
    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:

代码语言:javascript复制
    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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