From 36accc72c6ee765c57f426911fba35fd1aa4a342 Mon Sep 17 00:00:00 2001
From: Tassadar2499 <34176883+Tassadar2499@users.noreply.github.com>
Date: Sun, 14 Mar 2021 20:43:28 +0500
Subject: [PATCH] F# and C# addings (#189)

* F# - Binary Search

* C# - Double selection sort

* quick sort - f#
---
 01_introduction_to_algorithms/f#/Program.fs   | 26 +++++++++++++
 .../csharp/double_selection_sort/Program.cs   | 39 +++++++++++++++++++
 04_quicksort/f#/QuickSort/Program.fs          | 21 ++++++++++
 3 files changed, 86 insertions(+)
 create mode 100644 01_introduction_to_algorithms/f#/Program.fs
 create mode 100644 02_selection_sort/csharp/double_selection_sort/Program.cs
 create mode 100644 04_quicksort/f#/QuickSort/Program.fs

diff --git a/01_introduction_to_algorithms/f#/Program.fs b/01_introduction_to_algorithms/f#/Program.fs
new file mode 100644
index 0000000..f081473
--- /dev/null
+++ b/01_introduction_to_algorithms/f#/Program.fs
@@ -0,0 +1,26 @@
+// Learn more about F# at http://fsharp.org
+
+open System
+
+[<EntryPoint>]
+let main argv =
+    let numbers = [|1; 2; 3; 4; 5; 6; 7; 8; 9; 10|]
+
+    let rec binarySearch(arr: int[], number: int, startIndex: int, endIndex: int) : int
+        = 
+            let averageIndex = (startIndex + endIndex) / 2
+            let middleElement = arr.[averageIndex]
+
+            if (middleElement > number)
+                then binarySearch(arr, number, startIndex, averageIndex)
+            else if (middleElement < number)
+                then binarySearch(arr, number, averageIndex, endIndex)
+            else
+                averageIndex
+
+    let binarySearch(arr: int[], number: int)
+        = binarySearch(arr, number, 0, arr.Length)
+
+    let index = binarySearch(numbers, 7)
+    Console.WriteLine(index);
+    0
diff --git a/02_selection_sort/csharp/double_selection_sort/Program.cs b/02_selection_sort/csharp/double_selection_sort/Program.cs
new file mode 100644
index 0000000..153bb06
--- /dev/null
+++ b/02_selection_sort/csharp/double_selection_sort/Program.cs
@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace SelectionSort
+{
+	class Program
+	{
+		static void Main(string[] args)
+		{
+			var numbers = new int[] { 4, 5, 1, 3, 10, 9, 6, 8, 7, 2 };
+			var sortedArr = SelectionSort(numbers);
+
+			Console.WriteLine(string.Join(',', sortedArr));
+		}
+
+		private static int[] SelectionSort(int[] array) 
+			=> SelectionSort(new LinkedList<int>(array)).ToArray();
+
+		private static IEnumerable<int> SelectionSort(LinkedList<int> list)
+		{
+			var minList = new LinkedList<int>();
+			var maxList = new LinkedList<int>();
+
+			while (list.Count != 0)
+			{
+				var min = list.Min();
+				list.Remove(min);
+				minList.AddLast(min);
+
+				var max = list.Max();
+				list.Remove(max);
+				maxList.AddFirst(max);
+			}
+
+			return minList.Union(maxList);
+		}
+	}
+}
diff --git a/04_quicksort/f#/QuickSort/Program.fs b/04_quicksort/f#/QuickSort/Program.fs
new file mode 100644
index 0000000..e4b8884
--- /dev/null
+++ b/04_quicksort/f#/QuickSort/Program.fs
@@ -0,0 +1,21 @@
+// Learn more about F# at http://fsharp.org
+
+open System
+
+[<EntryPoint>]
+let main argv =
+    let numbers = [|3; 9; 10; 1; 4; 2; 6; 5; 8; 7|]
+
+    let rec quickSort(arr: int[]) =
+        if arr.Length < 2
+            then arr
+        else
+            let pivot = arr.[0]
+            let arrExcpetPivot = arr |> Seq.skip(1) |> Seq.toArray
+            let lessElements = quickSort arrExcpetPivot |> Seq.filter(fun n -> n <= pivot) |> Seq.toArray
+            let greaterElements = quickSort arrExcpetPivot |> Seq.filter(fun n -> n > pivot) |> Seq.toArray
+            
+            Seq.append (Seq.append lessElements [|pivot|]) greaterElements |> Seq.toArray
+
+    let sorted = quickSort(numbers)
+    0