min absolute diff in an array problem: C# solution

Algorithms/Greedy/Minimum Absolute Difference in an Array/Solution.cs

@@ -0,0 +1,78 @@
+/*
+         Problem: https://www.hackerrank.com/challenges/minimum-absolute-difference-in-an-array/problem
+         C# Language Version: 6.0
+         .Net Framework Version: 4.7
+         Tool Version : Visual Studio Community 2017
+         Thoughts :
+         1. Sort the input
+         2. Iterate the sorted input and track the absolute difference between adjacent elements
+         3. Print the minimum difference thus found.
+
+         Time Complexity:  O(n log(n)) //actually it is O(n log(n)) + O(n)
+         Space Complexity: O(n) //need to store all the elements in  memory for processing as sorting using quick sort is also involved.
+
+*/
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+class Solution
+{
+    static void Main(string[] args)
+    {
+        //No need to capture the size of array. We can use array's length property instead.
+        Console.ReadLine();
+        var arr_temp = Console.ReadLine().Split(' ');
+        var inputNumbers = Array.ConvertAll(arr_temp, int.Parse);
+        //contributes O(n log(n)) complexity
+        inputNumbers = QuickSort2(inputNumbers);
+        var minimumDiff = Math.Abs(inputNumbers[0] - inputNumbers[1]);
+        //contributes O(n) complexity
+        for (var i = 1; i < inputNumbers.Length - 1; i++)
+            minimumDiff = Math.Min(Math.Abs(inputNumbers[i] - inputNumbers[i + 1]), minimumDiff);
+
+        Console.WriteLine(minimumDiff);
+    }
+
+    static int[] QuickSort2(int[] arr)
+    {
+        var pivot = arr[0];
+        var smallerItems = new List<int>();
+        var equalItems = new List<int>();
+        var biggerItems = new List<int>();
+        var outputArr = new int[arr.Length];
+
+        equalItems.Add(arr[0]);
+
+        for (var i = 1; i < arr.Length; i++)
+        {
+            if (arr[i] < pivot)
+                smallerItems.Add(arr[i]);
+            else if (arr[i] > pivot)
+            {
+                biggerItems.Add(arr[i]);
+            }
+            else
+                equalItems.Add(arr[i]);
+        }
+
+        if (smallerItems.Count > 1)
+            smallerItems = QuickSort2(smallerItems.ToArray()).ToList();
+
+        if (biggerItems.Count > 1)
+            biggerItems = QuickSort2(biggerItems.ToArray()).ToList();
+
+        var j = 0;
+
+        foreach (var item in smallerItems)
+            outputArr[j++] = item;
+
+        foreach (var item in equalItems)
+            outputArr[j++] = item;
+
+        foreach (var item in biggerItems)
+            outputArr[j++] = item;
+
+        return outputArr;
+    }
+}

README.md

@@ -326,7 +326,7 @@
 ### Greedy
 | #  | Title           |  Solution       |  Time           | Space           | Difficulty    | Points          | Note
 -----|---------------- |:---------------:| --------------- | --------------- |:-------------:|:--------------:| -----
-|   | [Minimum Absolute Difference in an Array](https://www.hackerrank.com/challenges/minimum-absolute-difference-in-an-array)| <ul><li>[Java](./Algorithms/Greedy/Minimum%20Absolute%20Difference%20in%20an%20Array/Solution.java)</li> <li>[JS](./Algorithms/Greedy/Minimum%20Absolute%20Difference%20in%20an%20Array/Solution.js)</li><ul> | _O(n log(n))_ | _O(1)_ | Easy | 15| ||
+|   | [Minimum Absolute Difference in an Array](https://www.hackerrank.com/challenges/minimum-absolute-difference-in-an-array)| <ul><li>[Java](./Algorithms/Greedy/Minimum%20Absolute%20Difference%20in%20an%20Array/Solution.java)</li> <li>[JS](./Algorithms/Greedy/Minimum%20Absolute%20Difference%20in%20an%20Array/Solution.js)</li><li>[C#](./Algorithms/Greedy/Minimum%20Absolute%20Difference%20in%20an%20Array/Solution.cs)</li><ul> | _O(n log(n))_ | _O(n)_ | Easy | 15| ||
 |  |[Chief Hopper](https://www.hackerrank.com/challenges/chief-hopper)| <ul><li>[Java](./Algorithms/Greedy/Chief%20Hopper/Solution.java)</li><ul> | _O(n)_ | _O(n)_| Hard | 65 | ||
 |  |[Mark and Toys](https://www.hackerrank.com/challenges/mark-and-toys)| <ul><li>[Java](./Algorithms/Greedy/Mark%20and%20Toys/Solution.java)</li> <li>[JS](./Algorithms/Greedy/Mark%20and%20Toys/Solution.js)</li><ul> | _O(n log(n))_ | _O(n)_| Easy | 35 | ||
 |  | [Marc's Cakewalk](https://www.hackerrank.com/challenges/marcs-cakewalk)| <ul><li>[Java](./Algorithms/Greedy/Marc's%20Cakewalk/Solution.java)</li><ul> | _O(n + k)_ | _O(k)_ | Easy | 15| ||