# 1743. Restore the Array From Adjacent Pairs

https://leetcode.com/problems/restore-the-array-from-adjacent-pairs

## Description

There is an integer array `nums` that consists of `n` **unique** elements, but you have forgotten it. However, you do remember every pair of adjacent elements in `nums`.

You are given a 2D integer array `adjacentPairs` of size `n - 1` where each `adjacentPairs[i] = [ui, vi]` indicates that the elements `ui` and `vi` are adjacent in `nums`.

It is guaranteed that every adjacent pair of elements `nums[i]` and `nums[i+1]` will exist in `adjacentPairs`, either as `[nums[i], nums[i+1]]` or `[nums[i+1], nums[i]]`. The pairs can appear **in any order**.

Return _the original array_ `nums`_. If there are multiple solutions, return **any of them**_.

**Example 1:**

```
**Input:** adjacentPairs = [[2,1],[3,4],[3,2]]
**Output:** [1,2,3,4]
**Explanation:** This array has all its adjacent pairs in adjacentPairs.
Notice that adjacentPairs[i] may not be in left-to-right order.
```

**Example 2:**

```
**Input:** adjacentPairs = [[4,-2],[1,4],[-3,1]]
**Output:** [-2,4,1,-3]
**Explanation:** There can be negative numbers.
Another solution is [-3,1,4,-2], which would also be accepted.
```

**Example 3:**

```
**Input:** adjacentPairs = [[100000,-100000]]
**Output:** [100000,-100000]
```

**Constraints:**

* `nums.length == n`
* `adjacentPairs.length == n - 1`
* `adjacentPairs[i].length == 2`
* `2 <= n <= 105`
* `-105 <= nums[i], ui, vi <= 105`
* There exists some `nums` that has `adjacentPairs` as its pairs.

## ac

```java
```
