You are given a string s and an integer k.
First, you are allowed to change at most one index in s to another lowercase English letter.
After that, do the following partitioning operation until s is empty:
s containing at most k distinct characters.s and increase the number of partitions by one. The remaining characters (if any) in s maintain their initial order.Return an integer denoting the maximum number of resulting partitions after the operations by optimally choosing at most one index to change.
Example 1:
Input: s = "accca", k = 2
Output: 3
Explanation:
The optimal way is to change s[2] to something other than a and c, for example, b. then it becomes "acbca".
Then we perform the operations:
"ac", we remove it and s becomes "bca"."bc", so we remove it and s becomes "a"."a" and s becomes empty, so the procedure ends.Doing the operations, the string is divided into 3 partitions, so the answer is 3.
Example 2:
Input: s = "aabaab", k = 3
Output: 1
Explanation:
Initially s contains 2 distinct characters, so whichever character we change, it will contain at most 3 distinct characters, so the longest prefix with at most 3 distinct characters would always be all of it, therefore the answer is 1.
Example 3:
Input: s = "xxyz", k = 1
Output: 4
Explanation:
The optimal way is to change s[0] or s[1] to something other than characters in s, for example, to change s[0] to w.
Then s becomes "wxyz", which consists of 4 distinct characters, so as k is 1, it will divide into 4 partitions.
Constraints:
1 <= s.length <= 104s consists only of lowercase English letters.1 <= k <= 26NeetCodeIO