using System;

public class Program

{

    public static void Main()

    {

        // Console.WriteLine("GetClosestPoints([1, 2, 5])                -→ e:[1, 2]  |  a:" + GetClosestPoints(new int[] { 1, 2, 5 }));

        // Console.WriteLine("GetClosestPoints([1, 2, 3])                -→ e:[2, 3]  |  a:" + GetClosestPoints(new int[] { 1, 2, 3 }));

​

        Console.WriteLine(GetClosestPoints([1, 2, 5]));

        Console.WriteLine(GetClosestPoints([1, 2, 3]));

        Console.WriteLine(GetClosestPoints([1, 2, 3, 5, 6, 7, 8]));

        Console.WriteLine(GetClosestPoints([1, 2, 0, 1]));

        Console.WriteLine(GetClosestPoints([2, 0, 1]));

        Console.WriteLine(GetClosestPoints([0, 1, 2, -1]));

        Console.WriteLine(GetClosestPoints([-1, -2, 0]));

        Console.WriteLine(GetClosestPoints([-1, -2, 0, 1, 2]));

        Console.WriteLine(GetClosestPoints([100, 120, 140, 115]));

        Console.WriteLine(GetClosestPoints([2147483647, 2147483647, 1000, 1001]));

        Console.WriteLine(GetClosestPoints([2147483646, 2147483647, 1000, 1001]));

        Console.WriteLine(GetClosestPoints([]));

        Console.WriteLine(GetClosestPoints([4,3,2,1]));

​

    }

​

    // Given an array of numbers, return the 2 numbers that

    // has the minimum distance between any pair in the given numbers.

    // If there are multiple pairs with minimum distance, then return the pair

    // that contains the numbers that occurs last in the array.

    // ie:

    //   [1, 2, 5] --> [1, 2]

    //   [1, 2, 3] --> [2, 3]

    //

    // NOTE:

    // 1. You are NOT ALLOWED to create/instantiate any new collection (List, Array, Dictionary, etc)

    // 2. You are ALLOWED to create any number of local variables.

    public static ClosestPoints? GetClosestPoints(int[] points)

    {

        int num1Idx = 0;

        int num2Idx = 0;

        int minDistance = int.MaxValue;

​

        if (points != null && points.Length > 0)

        {

            for (int i = 0; i < points.Length; i++)

            {

                for (int j = i + 1; j < points.Length; j++)

                {

                    int distance = Math.Abs(points[i] - points[j]);

​

                    //Update if a shorter distance is found, or if distance is the same but pair occurs last.

                    if (distance < minDistance ||

                        (distance == minDistance && (j > num2Idx || (j == num2Idx && i > num1Idx))))

                    {

                        minDistance = distance;

                        num1Idx = i;

                        num2Idx = j;

                    }

                }

            }

​

​

            return new ClosestPoints(points[num1Idx], points[num2Idx]);

        }

​

        return null;

    }

}

​

public class ClosestPoints

{

    public ClosestPoints() { }

​

    public ClosestPoints(int p1, int p2)

    {

        P1 = p1;

        P2 = p2;

    }

​

    public int P1 { get; set; }

    public int P2 { get; set; }

​

    public override string ToString()

    {

        return $"[{P1}, {P2}]";

    }

​

}