Package g2001_2100.s2097_valid_arrangement_of_pairs

Class Solution

java.lang.Object

g2001_2100.s2097_valid_arrangement_of_pairs.Solution

public class Solution
extends Object

2097 - Valid Arrangement of Pairs.

Hard

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 end_i-1 always equals start_i.

end₀ = 9 == 9 = start₁

end₁ = 4 == 4 = start₂

end₂ = 5 == 5 = start₃

Example 2:

Input: pairs = [[1,3],[3,2],[2,1]]

Output: [[1,3],[3,2],[2,1]]

Explanation:

This is a valid arrangement since end_i-1 always equals start_i.

end₀ = 3 == 3 = start₁

end₁ = 2 == 2 = start₂

The arrangements [[2,1],[1,3],[3,2]] and [[3,2],[2,1],[1,3]] are also valid.

Example 3:

Input: pairs = [[1,2],[1,3],[2,1]]

Output: [[1,2],[2,1],[1,3]]

Explanation:

This is a valid arrangement since end_i-1 always equals start_i.

end₀ = 2 == 2 = start₁

end₁ = 1 == 1 = start₂

Constraints:

• 1 <= pairs.length <= 105
• pairs[i].length == 2
• 0 <= starti, endi <= 109
• starti != endi
• No two pairs are exactly the same.
• There exists a valid arrangement of pairs.

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int[][]	validArrangement(int[][] pairs)

Methods inherited from class java.lang.Object

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

Constructor Details

Solution

public Solution()

Method Details

validArrangement

public int[][] validArrangement(int[][] pairs)