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# 1640. Check Array Formation Through Concatenation

<https://leetcode.com/problems/check-array-formation-through-concatenation>

## Description

You are given an array of **distinct** integers `arr` and an array of integer arrays `pieces`, where the integers in `pieces` are **distinct**. Your goal is to form `arr` by concatenating the arrays in `pieces` **in any order**. However, you are **not** allowed to reorder the integers in each array `pieces[i]`.

Return `true` *if it is possible* *to form the array* `arr` *from* `pieces`. Otherwise, return `false`.

**Example 1:**

```
**Input:** arr = [85], pieces = [[85]]
**Output:** true
```

**Example 2:**

```
**Input:** arr = [15,88], pieces = [[88],[15]]
**Output:** true
**Explanation:** Concatenate [15] then [88]
```

**Example 3:**

```
**Input:** arr = [49,18,16], pieces = [[16,18,49]]
**Output:** false
**Explanation:** Even though the numbers match, we cannot reorder pieces[0].
```

**Example 4:**

```
**Input:** arr = [91,4,64,78], pieces = [[78],[4,64],[91]]
**Output:** true
**Explanation:** Concatenate [91] then [4,64] then [78]
```

**Example 5:**

```
**Input:** arr = [1,3,5,7], pieces = [[2,4,6,8]]
**Output:** false
```

**Constraints:**

* `1 <= pieces.length <= arr.length <= 100`
* `sum(pieces[i].length) == arr.length`
* `1 <= pieces[i].length <= arr.length`
* `1 <= arr[i], pieces[i][j] <= 100`
* The integers in `arr` are **distinct**.
* The integers in `pieces` are **distinct** (i.e., If we flatten pieces in a 1D array, all the integers in this array are distinct).

## ac

```java
```