mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-11-04 11:43:12 +08:00
53 lines
2.5 KiB
HTML
53 lines
2.5 KiB
HTML
<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 = "ababc"</code>, then in one operation, you could delete the first two letters of <code>s</code> to get <code>"abc"</code>, since the first two letters of <code>s</code> and the following two letters of <code>s</code> are both equal to <code>"ab"</code>.</p>
|
|
|
|
<p>Return <em>the <strong>maximum</strong> number of operations needed to delete all of </em><code>s</code>.</p>
|
|
|
|
<p> </p>
|
|
<p><strong class="example">Example 1:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> s = "abcabcdabc"
|
|
<strong>Output:</strong> 2
|
|
<strong>Explanation:</strong>
|
|
- 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.
|
|
</pre>
|
|
|
|
<p><strong class="example">Example 2:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> s = "aaabaab"
|
|
<strong>Output:</strong> 4
|
|
<strong>Explanation:</strong>
|
|
- 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.
|
|
</pre>
|
|
|
|
<p><strong class="example">Example 3:</strong></p>
|
|
|
|
<pre>
|
|
<strong>Input:</strong> s = "aaaaa"
|
|
<strong>Output:</strong> 5
|
|
<strong>Explanation:</strong> In each operation, we can delete the first letter of s.
|
|
</pre>
|
|
|
|
<p> </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>
|