2269. Find the K-Beauty of a Number

The k-beauty of an integer num is defined as the number of substrings of num when it is read as a string that meet the following conditions:

• It has a length of k.
• It is a divisor of num.
  Given integers num and k, return the k-beauty of num.

Note:

• Leading zeros are allowed.
• 0 is not a divisor of any value.

A substring is a contiguous sequence of characters in a string.

class Solution {
public:
    int divisorSubstrings(int num, int k) {
        string n = to_string(num);
        int res = 0;
        for(int i = 0; i <= n.length() - k; i++) {
            int div = stoi(n.substr(i, k));
            if(div and num % div == 0) {
                res++;
            }
        }
        return res;
    }
};