public class Solution
extends Object
2370 - Longest Ideal Subsequence\.
Medium
You are given a string `s` consisting of lowercase letters and an integer `k`. We call a string `t` **ideal** if the following conditions are satisfied:
* `t` is a **subsequence** of the string `s`.
* The absolute difference in the alphabet order of every two **adjacent** letters in `t` is less than or equal to `k`.
Return _the length of the **longest** ideal string_.
A **subsequence** is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.
**Note** that the alphabet order is not cyclic. For example, the absolute difference in the alphabet order of `'a'` and `'z'` is `25`, not `1`.
**Example 1:**
**Input:** s = "acfgbd", k = 2
**Output:** 4
**Explanation:** The longest ideal string is "acbd". The length of this string is 4, so 4 is returned. Note that "acfgbd" is not ideal because 'c' and 'f' have a difference of 3 in alphabet order.
**Example 2:**
**Input:** s = "abcd", k = 3
**Output:** 4
**Explanation:** The longest ideal string is "abcd". The length of this string is 4, so 4 is returned.
**Constraints:**
* 1 <= s.length <= 105
* `0 <= k <= 25`
* `s` consists of lowercase English letters.