Find the K-Beauty of a Number.cpp

// Runtime: 0 ms (Top 100.00%) | Memory: 6 MB (Top 61.38%)
class Solution {
public:
    int divisorSubstrings(int num, int k) {
        string str = to_string(num);
        int i = 0, j = 0, n = str.length();
        int ind = 0;

        while(j < n)
        {
            if(j - i + 1 < k)
            {
            // increment j till we get the window size
                ++j;
            }
            else if(j - i + 1 == k)
            {
            // on hiting the window size
            // extract window string and convert to int
            // check if it follows the given condition
                string s = str.substr(i,k);
                int n = stoi(s);
                if(n != 0 && num % n == 0 )
                    ++ind;

                // shift the window by ++j;
                // remove previous calculation by ++i
                ++i;
                ++j;
            }

        }

        return ind;
    }
};