Package g2401_2500.s2430_maximum_deletions_on_a_string

Class Solution

  • public class Solution
extends Object
    2430 - Maximum Deletions on a String.

    Hard

    You are given a string s consisting of only lowercase English letters. In one operation, you can:

    • Delete the entire string s, or
    • Delete the first i letters of s if the first i letters of s are equal to the following i letters in s, for any i in the range 1 <= i <= s.length / 2.

    For example, if s = "ababc", then in one operation, you could delete the first two letters of s to get "abc", since the first two letters of s and the following two letters of s are both equal to "ab".

    Return the maximum number of operations needed to delete all of s.

    Example 1:

    Input: s = “abcabcdabc”

    Output: 2

    Explanation:

    • Delete the first 3 letters (“abc”) since the next 3 letters are equal. Now, s = “abcdabc”.

    • Delete all the letters.

    We used 2 operations so return 2. It can be proven that 2 is the maximum number of operations needed.

    Note that in the second operation we cannot delete “abc” again because the next occurrence of “abc” does not happen in the next 3 letters.

    Example 2:

    Input: s = “aaabaab”

    Output: 4

    Explanation:

    • Delete the first letter (“a”) since the next letter is equal. Now, s = “aabaab”.

    • Delete the first 3 letters (“aab”) since the next 3 letters are equal. Now, s = “aab”.

    • Delete the first letter (“a”) since the next letter is equal. Now, s = “ab”.

    • Delete all the letters.

    We used 4 operations so return 4. It can be proven that 4 is the maximum number of operations needed.

    Example 3:

    Input: s = “aaaaa”

    Output: 5

    Explanation: In each operation, we can delete the first letter of s.

    Constraints:

    • 1 <= s.length <= 4000
    • s consists only of lowercase English letters.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • deleteString

        public int deleteString​(String s)