# 1743. Restore the Array From Adjacent Pairs

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.

Medium

Normal

Robinhood