728. Self Dividing Numbers

Posted 2021-02-28 dysjtu1995

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：

Solution (C++):

vector<int> selfDividingNumbers(int left, int right) {
    vector<int> res;
    for (int i = left; i <= right; ++i) {
        if (isSelfDividing(i))  res.push_back(i);
    }
    return res;
}
bool isSelfDividing(int n) {
    if (n == 0)  return false;
    if (n < 10)  return true;
    vector<int> vec;
    int tmp = n;
    while (n) {
        if (n%10 == 0)  return false;
        vec.push_back(n%10);
        n /= 10;
    }
    for (auto v : vec) {
        if (tmp % v)  return false;
    }
    return true;
}

性能：

Runtime: 40 ms??Memory Usage: 10.6 MB

思路：

Solution (C++):

性能：

Runtime: ms??Memory Usage: MB