Longest Ideal Subsequence LeetCode solution in Python

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class Solution:
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    def longestIdealString(self, s: str, k: int) -> int:
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        dp = [0] * 26
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        for ch in s:
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            i = ord(ch) - ord("a")
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            dp[i] = 1 + max(dp[max(0, i - k) : min(26, i + k + 1)])
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        return max(dp)