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Md Ariful Haque @mah-shamim

Valid Arrangement Of Pairs In 60 Characters

Convert pairs into graph problem, find Eulerian path using Hierholzer's algorithm, return valid arrangement of pairs.

2097. Valid Arrangement of Pairs
Difficulty: Hard
Topics: Depth-First Search, Graph, Eulerian Circuit
You are given a 0-indexed 2D integer array pairs where pairs[i] = [starti, endi]. An arrangement of pairs is valid if for every index i where 1 <= i < pairs.length, we have endi-1 == starti.
Return any valid arrangement of pairs.
Note: The inputs will be generated such that there exists a valid arrangement of pairs.
Example 1:

Input: pairs = [[5,1],[4,5],[11,9],[9,4]]
Output: [[11,9],[9,4],[4,5],[5,1]]
Explanation: This is a valid arrangement since endi-1 always equals starti.

end0 = 9 == 9...