Question
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'
.
Python Solution
class Solution: def removePalindromeSub(self, s: str) -> int: if s=="": return 0 elif s==s[::-1]: return 1 else: return 2