Package g1701_1800.s1743_restore_the_array_from_adjacent_pairs

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    1743 - Restore the Array From Adjacent Pairs.

    Medium

    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 <code>adjacentPairsi = u<sub>i</sub>, v<sub>i</sub></code> indicates that the elements <code>u<sub>i</sub></code> and <code>v<sub>i</sub></code> 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 adjacentPairsi 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

    • <code>2 <= n <= 10<sup>5</sup></code>

    • <code>-10<sup>5</sup><= numsi, u<sub>i</sub>, v<sub>i</sub><= 10<sup>5</sup></code>

    • There exists some nums that has adjacentPairs as its pairs.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final IntArray restoreArray(Array<IntArray> adjacentPairs)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait