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# 2000. Reverse Prefix of Word

<https://leetcode.com/problems/reverse-prefix-of-word>

## Description

Given a **0-indexed** string `word` and a character `ch`, **reverse** the segment of `word` that starts at index `0` and ends at the index of the **first occurrence** of `ch` (**inclusive**). If the character `ch` does not exist in `word`, do nothing.

* For example, if `word = "abcdefd"` and `ch = "d"`, then you should **reverse** the segment that starts at `0` and ends at `3` (**inclusive**). The resulting string will be `"dcbaefd"`.

Return *the resulting string*.

**Example 1:**

```
**Input:** word = "abcdefd", ch = "d"
**Output:** "dcbaefd"
**Explanation:** The first occurrence of "d" is at index 3. 
Reverse the part of word from 0 to 3 (inclusive), the resulting string is "dcbaefd".
```

**Example 2:**

```
**Input:** word = "xyxzxe", ch = "z"
**Output:** "zxyxxe"
**Explanation:** The first and only occurrence of "z" is at index 3.
Reverse the part of word from 0 to 3 (inclusive), the resulting string is "zxyxxe".
```

**Example 3:**

```
**Input:** word = "abcd", ch = "z"
**Output:** "abcd"
**Explanation:** "z" does not exist in word.
You should not do any reverse operation, the resulting string is "abcd".
```

**Constraints:**

* `1 <= word.length <= 250`
* `word` consists of lowercase English letters.
* `ch` is a lowercase English letter.

## ac

```java
```