# 1332. Remove Palindromic Subsequences

https://leetcode.com/problems/remove-palindromic-subsequences/

You are given a string s consisting only of letters ‘a’ and ‘b’. In a single step you can remove one palindromic subsequence from s. Return the minimum number of steps to make the given string empty. A string is a subsequence of a given string if it is generated by deleting some characters of a given string without changing its order. Note that a subsequence does not necessarily need to be contiguous. A string is called palindrome if is one that reads the same backward as well as forward.

Example 1: Input: s = “ababa” Output: 1 Explanation: s is already a palindrome, so its entirety can be removed in a single step. Example 2: Input: s = “abb” Output: 2 Explanation: “abb” -> “bb” -> “”. Remove palindromic subsequence “a” then “bb”. Example 3: Input: s = “baabb” Output: 2 Explanation: “baabb” -> “b” -> “”. Remove palindromic subsequence “baab” then “b”.

Constraints:

``````1 <= s.length <= 1000
s[i] is either 'a' or 'b'.
``````

• code
``````class Solution:
def removePalindromeSub(self, s: str) -> int:
if not s: return 0
return 1 if s == s[::-1] else 2
``````