Palindrome Partitioning II

Description

Given a string s, partition s such that every substring of the partition is a palindrome.

Return the minimum cuts needed for a palindrome partitioning of s.

 

Example 1:

Input: s = "aab"
Output: 1
Explanation: The palindrome partitioning ["aa","b"] could be produced using 1 cut.

Example 2:

Input: s = "a"
Output: 0

Example 3:

Input: s = "ab"
Output: 1

 

Constraints:

• 1 <= s.length <= 2000
• s consists of lowercase English letters only.

Solution(python3)

class Solution:
    def minCut(self, s: str) -> int:
        length = len(s)
        cuts = [i for i in range(length)]

        for i in range(length):
            # Odd size palindrome
            j = 0 # one-character palindrome when j == 0
            while i - j >= 0 and i + j < length and s[i - j] == s[i + j]:
                prev_cuts = cuts[i - j - 1] if i - j - 1 >= 0 else -1
                cuts[i + j] = min(cuts[i + j], prev_cuts + 1)
                j += 1

            # Even size palindrome
            j = 0
            while i - j >= 0 and i + j + 1 < length and s[i - j] == s[i + j + 1]:
                prev_cuts = cuts[i - j - 1] if i - j - 1 >= 0 else -1
                cuts[i + j + 1] = min(cuts[i + j + 1], prev_cuts + 1)
                j += 1

        return cuts[-1]