#1147

Longest Chunked Palindrome Decomposition

hard · verified · 59% accepted · 710 likes · top 56%

two pointers · string · dynamic programming · greedy · rolling hash · hash function

⊣ practice⊣ open on leetcode ↗

Description

You are given a string text. You should split it to k substrings (subtext1, subtext2, ..., subtextk) such that:

- subtexti is a non-empty string.

- The concatenation of all the substrings is equal to text (i.e., subtext1 + subtext2 + ... + subtextk == text).

- subtexti == subtextk - i + 1 for all valid values of i (i.e., 1 <= i <= k).

Return the largest possible value of k.

Example 1:

Input: text = "ghiabcdefhelloadamhelloabcdefghi"
Output: 7
Explanation: We can split the string on "(ghi)(abcdef)(hello)(adam)(hello)(abcdef)(ghi)".

Example 2:

Input: text = "merchant"
Output: 1
Explanation: We can split the string on "(merchant)".

Example 3:

Input: text = "antaprezatepzapreanta"
Output: 11
Explanation: We can split the string on "(a)(nt)(a)(pre)(za)(tep)(za)(pre)(a)(nt)(a)".

Solution