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 Object

2430 - Maximum Deletions on a String.<p>Hard</p> <p>You are given a string <code>s</code> consisting of only lowercase English letters. In one operation, you can:</p> <ul> <li>Delete <strong>the entire string</strong> <code>s</code>, or</li> <li>Delete the <strong>first</strong> <code>i</code> letters of <code>s</code> if the first <code>i</code> letters of <code>s</code> are <strong>equal</strong> to the following <code>i</code> letters in <code>s</code>, for any <code>i</code> in the range <code>1 <= i <= s.length / 2</code>.</li> </ul> <p>For example, if <code>s = &quot;ababc&quot;</code>, then in one operation, you could delete the first two letters of <code>s</code> to get <code>&quot;abc&quot;</code>, since the first two letters of <code>s</code> and the following two letters of <code>s</code> are both equal to <code>&quot;ab&quot;</code>.</p> <p>Return <em>the <strong>maximum</strong> number of operations needed to delete all of</em> <code>s</code>.</p> <p><strong>Example 1:</strong></p> <p><strong>Input:</strong> s = &ldquo;abcabcdabc&rdquo;</p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong></p> <ul> <li> <p>Delete the first 3 letters (&ldquo;abc&rdquo;) since the next 3 letters are equal. Now, s = &ldquo;abcdabc&rdquo;.</p> </li> <li> <p>Delete all the letters.</p> </li> </ul> <p>We used 2 operations so return 2. It can be proven that 2 is the maximum number of operations needed.</p> <p>Note that in the second operation we cannot delete &ldquo;abc&rdquo; again because the next occurrence of &ldquo;abc&rdquo; does not happen in the next 3 letters.</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> s = &ldquo;aaabaab&rdquo;</p> <p><strong>Output:</strong> 4</p> <h2 id="explanation"><a href="#explanation" id="explanation"><strong>Explanation:</strong></a></h2> <ul> <li> <p>Delete the first letter (&ldquo;a&rdquo;) since the next letter is equal. Now, s = &ldquo;aabaab&rdquo;.</p> </li> <li> <p>Delete the first 3 letters (&ldquo;aab&rdquo;) since the next 3 letters are equal. Now, s = &ldquo;aab&rdquo;.</p> </li> <li> <p>Delete the first letter (&ldquo;a&rdquo;) since the next letter is equal. Now, s = &ldquo;ab&rdquo;.</p> </li> <li> <p>Delete all the letters.</p> </li> </ul> <p>We used 4 operations so return 4. It can be proven that 4 is the maximum number of operations needed.</p> <p><strong>Example 3:</strong></p> <p><strong>Input:</strong> s = &ldquo;aaaaa&rdquo;</p> <p><strong>Output:</strong> 5</p> <p><strong>Explanation:</strong> In each operation, we can delete the first letter of s.</p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= s.length <= 4000</code></li> <li><code>s</code> consists only of lowercase English letters.</li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	deleteString(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(String s)