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# 1961. Check If String Is a Prefix of Array

<https://leetcode.com/problems/check-if-string-is-a-prefix-of-array>

## Description

Given a string `s` and an array of strings `words`, determine whether `s` is a **prefix string** of `words`.

A string `s` is a **prefix string** of `words` if `s` can be made by concatenating the first `k` strings in `words` for some **positive** `k` no larger than `words.length`.

Return `true` *if* `s` *is a **prefix string** of* `words`*, or* `false` *otherwise*.

**Example 1:**

```
**Input:** s = "iloveleetcode", words = ["i","love","leetcode","apples"]
**Output:** true
**Explanation:**
s can be made by concatenating "i", "love", and "leetcode" together.
```

**Example 2:**

```
**Input:** s = "iloveleetcode", words = ["apples","i","love","leetcode"]
**Output:** false
**Explanation:**
It is impossible to make s using a prefix of arr.
```

**Constraints:**

* `1 <= words.length <= 100`
* `1 <= words[i].length <= 20`
* `1 <= s.length <= 1000`
* `words[i]` and `s` consist of only lowercase English letters.

## ac

```java
```