Package g1701_1800.s1743_restore_the_array_from_adjacent_pairs

Class Solution

  • public class Solution
extends Object
    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 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.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • restoreArray

        public int[] restoreArray​(int[][] adjacentPairs)