Package g2401_2500.s2430_maximum_deletions_on_a_string

Class Solution

java.lang.Object
g2401_2500.s2430_maximum_deletions_on_a_string.Solution
public class Solution extends java.lang.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 Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    deleteString(java.lang.String s)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • deleteString

      public int deleteString(java.lang.String s)