Leetcode 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 = 2Output: 2Explanation: 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 = 2Output: 2Explanation: 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.

难得的100%啊。。。

Runtime: 0 ms, faster than 100.00% of Java online submissions for Find the K-Beauty of a Number.

Memory Usage: 39.2 MB, less than 63.48% of Java online submissions for Find the K-Beauty of a Number.