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.
Solution
class Solution:
def divisorSubstrings(self, num: int, k: int) -> int:
s = str(num)
out = 0
for i in range(k, len(s)+1):
x = int((s[i-k:i]))
if x != 0 and num % x == 0:
out += 1
return out