README.md

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.

Example 1:

Input: num = 240, k = 2
Output: 2
Explanation: The following are the substrings of num of length k:
- "24" from "240": 24 is a divisor of 240.
- "40" from "240": 40 is a divisor of 240.
Therefore, the k-beauty is 2.

Example 2:

Input: num = 430043, k = 2
Output: 2
Explanation: The following are the substrings of num of length k:
- "43" from "430043": 43 is a divisor of 430043.
- "30" from "430043": 30 is not a divisor of 430043.
- "00" from "430043": 0 is not a divisor of 430043.
- "04" from "430043": 4 is not a divisor of 430043.
- "43" from "430043": 43 is a divisor of 430043.
Therefore, the k-beauty is 2.

Constraints:

• 1 <= num <= 109
• 1 <= k <= num.length (taking num as a string)

Solutions (Python)

1. Solution

class Solution:
    def divisorSubstrings(self, num: int, k: int) -> int:
        s = str(num)
        ret = 0

        for i in range(len(s) - k + 1):
            x = int(s[i:i + k])

            if x > 0 and num % x == 0:
                ret += 1

        return ret