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'
.

