From 0ca911387b8bf87f6093e51705ba8f9df526e0bd Mon Sep 17 00:00:00 2001
From: Toihir Halim <66559721+toihirhalim@users.noreply.github.com>
Date: Wed, 14 Apr 2021 17:31:22 +0200
Subject: [PATCH 01/11] Add trees pre in post traversal java (#178)

* add pre, in and post traversal trees in java

* Update README.md

* update line 49 to pass lint test

change "System.out.print("\n\nin order: ");
to
System.out.println("\n");
System.out.print("in order: ");
---
 trees/README.md                       |  4 ++
 trees/java/pre_in_post_traversal.java | 76 +++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)
 create mode 100644 trees/java/pre_in_post_traversal.java

diff --git a/trees/README.md b/trees/README.md
index 69807e1d..cf5eeaa6 100644
--- a/trees/README.md
+++ b/trees/README.md
@@ -5,3 +5,7 @@
 1. [Pre, In & Post Order Traversals](c-or-cpp/pre-in-post-traversal.cpp)
 2. [Level Order Traversal](c-or-cpp/level-order-traversal.cpp)
 3. [Build Binary Tree using Pre,In & Post Order](c-or-cpp/build-binary-tree.cpp)
+
+### Java
+
+1. [Pre, In & Post Order Traversals](java/pre_in_post_traversal.java)
diff --git a/trees/java/pre_in_post_traversal.java b/trees/java/pre_in_post_traversal.java
new file mode 100644
index 00000000..8997e3e3
--- /dev/null
+++ b/trees/java/pre_in_post_traversal.java
@@ -0,0 +1,76 @@
+class Node{  
+    int value;  
+    Node left;  
+    Node right;  
+
+    public Node(int value) {  
+        this.value = value;  
+    }  
+}
+
+public class pre_in_post_traversal{
+
+    public static void preOrder(Node node){
+        if (node == null) return;
+
+        System.out.print(node.value + ", ");
+        preOrder(node.left);
+        preOrder(node.right);
+    }
+
+    public static void inOrder(Node node){
+        if(node == null) return;
+
+        inOrder(node.left);
+        System.out.print(node.value + ", ");
+        inOrder(node.right);
+    }
+
+    public static void postOrder(Node node){
+        if(node == null) return;
+        postOrder(node.left);
+        postOrder(node.right);
+        System.out.print(node.value + ", ");
+    }
+
+
+    public static void main(String [] args){
+        Node root = new Node(4);
+        root.left = new Node(2);
+        root.right = new Node(7);
+        root.left.right = new Node(6);
+        root.left.left = new Node(1);
+        root.right.right = new Node(9);
+
+        System.out.print("pre order: ");
+        preOrder(root);
+        
+        System.out.println("\n");
+        System.out.print("in order: ");
+        inOrder(root);
+
+        System.out.print("\n\npost order: ");
+        postOrder(root);
+    }
+}
+
+/*
+tree structure:
+        4
+      /   \
+    2       7
+  /   \       \
+1      6       9
+
+to run the file:
+    javac .\pre_in_post_traversal.java
+    java pre_in_post_traversal
+
+results:
+    pre order: 4, 2, 1, 6, 7, 9, 
+
+    in order: 1, 2, 6, 4, 7, 9,
+
+    post order: 1, 6, 2, 9, 7, 4,
+
+*/

From d991c37cf19404257340be4e7517f9f7be87bf38 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Wed, 14 Apr 2021 20:37:20 +0200
Subject: [PATCH 02/11] Add Python doctests to singly linked list (#190)

---
 linked-lists/Python/singly.py | 140 +++++++++++++++++++++-------------
 1 file changed, 86 insertions(+), 54 deletions(-)

diff --git a/linked-lists/Python/singly.py b/linked-lists/Python/singly.py
index de5037c1..270a2145 100644
--- a/linked-lists/Python/singly.py
+++ b/linked-lists/Python/singly.py
@@ -1,58 +1,90 @@
-# A simple Python program to create a singly linked list 
-  
-# Node class 
-class Node: 
-  
-    # Function to initialise the node object 
-    def __init__(self, data): 
-        self.data = data  # Assign data 
-        self.next = None  # Initialize next as null 
-  
-  
-# Linked List class contains a Node object 
-class LinkedList: 
-  
-    # Function to initialize head 
-    def __init__(self): 
+# Create a singly linked list
+
+class Node:
+    def __init__(self, data):
+        self.data = data
+        self.next = None
+
+    def __repr__(self):
+        """
+        >>> Node(77)
+        Node(77)
+        """
+        return f"Node({self.data})"
+
+
+class LinkedList:
+    def __init__(self):
         self.head = None
 
-    
-    # Function to insert a new node at the beginning 
-    def insertAtHead(self, new_data): 
-    
-        # 1 & 2: Allocate the Node & 
-        #        Put in the data 
-        new_node = Node(new_data) 
-            
-        # 3. Make next of new Node as head 
-        new_node.next = self.head 
-            
-        # 4. Move the head to point to new Node  
-        self.head = new_node 
-    def removeAtHead(self):
-        temp = self.head 
- 
-        # If head node itself holds the key to be deleted 
-        if (temp is not None): 
-            self.head = temp.next
-            temp = None
-            return
-        else:
-            return('underflow')
-    def printList(self): 
-        temp = self.head 
-        while(temp): 
-            print (temp.data)
-            temp = temp.next
+    def __iter__(self):
+        """
+        >>> ll = LinkedList()
+        >>> list(ll)
+        []
+        >>> ll.push(88)
+        >>> tuple(ll)
+        (88,)
+        >>> ll.push(89)
+        >>> tuple(ll)
+        (89, 88)
+        """
+        node = self.head
+        while node:
+            yield node.data  # `yield node` would also be possible
+            node = node.next
 
-  
-  
-# Code execution starts here 
-if __name__=='__main__':
-    l=LinkedList()
-    l.insertAtHead(1)
-    l.insertAtHead('xyz')
-    l.insertAtHead(1.1)
-    l.removeAtHead()
-    l.printList()
+    def __len__(self):
+        return len(tuple(iter(self)))
 
+    def __repr__(self):
+        """
+        >>> ll = LinkedList()
+        >>> repr(ll)
+        'LinkedList()'
+        >>> ll.push(99)
+        >>> ll.push(100)
+        >>> repr(ll)
+        'LinkedList(100, 99)'
+        >>> str(ll)
+        'LinkedList(100, 99)'
+        """
+        return f"LinkedList({', '.join(str(node) for node in self)})"
+
+    def push(self, data):
+        node = Node(data)
+        node.next = self.head
+        self.head = node
+
+    def pop(self):
+        """
+        >>> ll = LinkedList()
+        >>> len(ll)
+        0
+        >>> ll.push("push/pop")
+        >>> len(ll)
+        1
+        >>> ll.pop()
+        'push/pop'
+        >>> len(ll)
+        0
+        >>> ll.pop()
+        Traceback (most recent call last):
+            ...
+        IndexError: pop from empty LinkedList
+        """
+        node = self.head
+        if not node:
+            raise IndexError("pop from empty LinkedList")
+        self.head = node.next
+        return node.data
+
+
+if __name__ == '__main__':
+    ll = LinkedList()
+    ll.push(1)
+    ll.push('xyz')
+    ll.push(1.1)
+    ll.pop()
+    print(ll)
+    print(list(ll))

From 6cb96b0d4492c2251dc0270a94450a4f1bc159b5 Mon Sep 17 00:00:00 2001
From: Aayush Jain <jaayush014@gmail.com>
Date: Thu, 15 Apr 2021 00:08:49 +0530
Subject: [PATCH 03/11] Added myself to reviewer's list. (#191)

* Clone linked list with random pointer

* addition in  reviewers list
---
 README.md | 44 +++++++++++++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/README.md b/README.md
index aea147c8..a5dca766 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,5 @@
 # Data Structures and Algorithm
+
 Data structure and Algorithm (DSA)
 
 ## Contribution Guidelines
@@ -7,13 +8,15 @@ Data structure and Algorithm (DSA)
 
 The problem being contributed must either be a simple **file** (**Eg.** [`kruskal-algorithm.cpp`](https://github.com/MakeContributions/DSA/blob/main/graphs/c-or-cpp/kruskal-algorithm.cpp), [`linear-search.java`](https://github.com/MakeContributions/DSA/blob/main/searching/java/linear-search.java)) or a more complex **directory** ([`palindrome/`](https://github.com/MakeContributions/DSA/tree/main/strings/rust/palindrome)). This is a unit `problem`.
 
-The directory tree has the following convention of `category/language/problem`, where `category` is the topic or category of the  problem being contributed (**Eg.** `strings`, `sorting`, `linked-lists` etc.), `language` represents the language code of the problem (**Eg.** `c-or-cpp` for C/C++, `python` for Python, `java` for Java etc.), and `problem` is a conforming name to the problem (**Eg.** `linear-search.cpp`, `palindrome`, `queue-linked-list.cpp` etc.)
+The directory tree has the following convention of `category/language/problem`, where `category` is the topic or category of the problem being contributed (**Eg.** `strings`, `sorting`, `linked-lists` etc.), `language` represents the language code of the problem (**Eg.** `c-or-cpp` for C/C++, `python` for Python, `java` for Java etc.), and `problem` is a conforming name to the problem (**Eg.** `linear-search.cpp`, `palindrome`, `queue-linked-list.cpp` etc.)
 
 A unit `problem` must conform to the following specifications:
+
 - The name should be in lowercase. (**Eg.** `palindrome/`, `binary-search.cpp` etc.).
 - Each word must be separated by a **dash** or a **hyphen** (`-`).
 
-**If you have a problem that belongs to a new *topic* or *category* than one which are present:**
+**If you have a problem that belongs to a new _topic_ or _category_ than one which are present:**
+
 1. Create a new folder and an index for it inside (a readme, `README.md` file).
 2. To each new index file, write the readme with your `problem` in it ([Markdown Documentation](https://guides.github.com/features/mastering-markdown/)).
 3. The folder name can also only contain **lowercase characters** and **dashes** or **hyphens** (`-`) (Eg. `strings` `sorting` etc.)
@@ -29,6 +32,7 @@ The project and folder-based contributions have a bit more stricter contribution
 The folder should conform to the `problem` specification, along with the following specifications
 
 **Folder Structure**
+
 ```bash
 problem-name\
 | - .gitignore
@@ -40,7 +44,7 @@ problem-name\
 
 #### `README.md` Specification / Template
 
-```markdown
+````markdown
 # <Title of the Problem>
 
 < description of the problem >
@@ -54,15 +58,17 @@ problem-name\
 
 - instructions to run the project
 - < Simple and reproducible commands to execute the project >
-    ```bash
-     make # or 'cargo run', or 'dotnet run' or 'mvn exec:java' etc.
-    ```
+  ```bash
+   make # or 'cargo run', or 'dotnet run' or 'mvn exec:java' etc.
+  ```
+
 ## Test Cases & Output < if exists>
 
 < If you can provide test cases, describe it here, else remove this section >
-```
+````
 
 #### `.gitignore` File
+
 ```gitignore
 # add all output files and build files to be excluded from git tracking
 main     # executable file also must have the project name
@@ -70,7 +76,9 @@ target/  # the build file, for example for rust
 ```
 
 #### Build File / Specification File / Configuration File
+
 It can be any of the following ones
+
 - **C/C++**: `Makefile`
 - **Python**: `requirements.txt`
 - **JavaScript**: `package.json` and `package-lock.json`
@@ -88,24 +96,30 @@ Again, the source codes must conform to a valid file structure convention that t
 The programming should keep the naming convention rule of each programming language.
 
 ### Other topic
+
 - [First-time contribution](CONTRIBUTING.md)
 
 ## Contributors
+
 <a href="https://github.com/MakeContributions/DSA/graphs/contributors">
   <img src="https://contrib.rocks/image?repo=MakeContributions/DSA" />
 </a>
 
 ### Reviewers
-|Programming Language| Users         |
-|-------------------|---------------|
-| C or C++          |@Arsenic-ATG, @UG-SEP  |
-| Java              |@TawfikYasser, @cyberwizard1001          |
-| C#                | @ming-tsai            |
-| Go                |@atin                  |
-| Python            | @Arsenic-ATG, @atin, @sridhar-5, @cyberwizard1001 |
-| JavaScript        | @paulsonjpaul         |
+
+| Programming Language | Users                                             |
+| -------------------- | ------------------------------------------------- |
+| C or C++             | @Arsenic-ATG, @UG-SEP, @aayushjain7               |
+| Java                 | @TawfikYasser, @cyberwizard1001, @aayushjain7     |
+| C#                   | @ming-tsai                                        |
+| Go                   | @atin                                             |
+| Python               | @Arsenic-ATG, @atin, @sridhar-5, @cyberwizard1001 |
+| JavaScript           | @paulsonjpaul                                     |
+
 ## Open Graph
+
 <img src="https://opengraph.github.com/3b128f0e88464a82a37f2daefd7d594c6f41a3c22b3bf94c0c030135039b5dd7/MakeContributions/DSA" />
 
 ## License
+
 [MIT](./LICENSE)

From 2f86af8736effc15f1f0a5be014f554679296319 Mon Sep 17 00:00:00 2001
From: JACOB JAMES K <jacobja3@gmail.com>
Date: Thu, 15 Apr 2021 00:24:00 +0530
Subject: [PATCH 04/11] Added Java Implementation of Dijkstras Algorithm for
 Single Source Shortest Path (#187)

* Added Java Implementation of Dijkstras Algorithm for Single Source Shortest Path

* Added changes to Dijkstras Algorithm Implementation according to review

* Corrected spelling mistakes
---
 graphs/README.md           |   4 ++
 graphs/java/Dijkstras.java | 133 +++++++++++++++++++++++++++++++++++++
 2 files changed, 137 insertions(+)
 create mode 100644 graphs/java/Dijkstras.java

diff --git a/graphs/README.md b/graphs/README.md
index b0806cc6..510a1ccc 100644
--- a/graphs/README.md
+++ b/graphs/README.md
@@ -5,3 +5,7 @@
 1. [Kruskal Algorithm](c-or-cpp/kruskal-algorithm.cpp)
 2. [Bellman Ford Algorithm](c-or-cpp/bellman-ford.cpp)
 3. [Prim's Algorithm](c-or-cpp/Prim's-algorithm.c)
+
+### Java
+
+1. [Dijkstras Algorithm](java/Dijkstras.java)
diff --git a/graphs/java/Dijkstras.java b/graphs/java/Dijkstras.java
new file mode 100644
index 00000000..9ac9fb16
--- /dev/null
+++ b/graphs/java/Dijkstras.java
@@ -0,0 +1,133 @@
+import java.util.*;
+
+class AdjListNode
+{
+	int dest;
+	int weight;
+	AdjListNode(int dest,int weight)
+	{
+		this.dest=dest;
+		this.weight=weight;
+	}
+}
+
+class NodeComparator implements Comparator<AdjListNode>
+{
+	@Override
+	public int compare(AdjListNode node1, AdjListNode node2) 
+	{		
+		if (node1.weight < node2.weight) 
+            		return -1; 
+        	if (node1.weight > node2.weight) 
+            		return 1; 
+        	return 0; 
+	}
+}
+
+class Dijkstras
+{
+	public int[] dijkstras(List<List<AdjListNode>> adj_list,int source)
+	{
+		int[] distance = new int[adj_list.size()];
+		Set<Integer> completed = new HashSet<Integer>();
+		for(int i=0;i<distance.length;++i)
+		{
+			distance[i] = Integer.MAX_VALUE;
+		}
+		PriorityQueue<AdjListNode> pq = new PriorityQueue<>(adj_list.size(),new NodeComparator());
+		AdjListNode source_node = new AdjListNode(source,0);
+		for(int i=0;i<distance.length;++i)
+		{
+			pq.add(new AdjListNode(i,Integer.MAX_VALUE));
+			
+		}
+		pq.add(source_node);
+		distance[source]=0;
+		while(!pq.isEmpty())
+		{
+			AdjListNode current = pq.remove();
+			if(!completed.contains(current.dest))
+			{
+				completed.add(current.dest);
+				for(AdjListNode n :adj_list.get(current.dest) )
+				{
+					if( distance[n.dest] > (distance[current.dest]+n.weight))
+					{
+						distance[n.dest] = distance[current.dest]+n.weight;
+						pq.add(new AdjListNode(n.dest, distance[n.dest]));
+					}
+				}
+			}
+		}
+		return distance;
+	}
+
+	public static void main(String args[])
+	{
+		/*
+		  	SAMPLE INPUT AND OUTPUT
+			___________________________
+
+			Input:
+			__________
+			Please enter the number of nodes N. Vertices will be [0,N-1]
+			6
+			Please Enter the number of Edges
+			9
+			Please enter each edge in the sequence <starting node> <destination node> <weight>
+			0 1 1
+			0 2 5
+			1 2 2
+			1 4 1
+			1 3 2
+			2 4 2
+			3 5 1
+			3 4 3
+			4 5 2
+			Please enter source vertex
+			0
+
+			Output:
+			___________
+			Distances from source 0
+			Node0--->0
+			Node1--->1
+			Node2--->3
+			Node3--->3
+			Node4--->2
+			Node5--->4
+		 */
+
+		List<List<AdjListNode>> adj_list = new ArrayList<List<AdjListNode>>();
+		System.out.println("Please enter the number of nodes N. Vertices will be [0,N-1]");
+		Scanner sc = new Scanner(System.in);
+		int v = sc.nextInt();
+		for(int i=0;i<v;++i)
+			adj_list.add(new ArrayList<AdjListNode>());
+		
+		System.out.println("Please enter the number of edges");
+		int e = sc.nextInt();
+		System.out.println("Please enter each edge in the sequence <starting node> <destination node> <weight>");
+		// Sample Data: 0 2 5 (edge from 0 to 2 with weight 5)
+		for(int i=0;i<e;++i)
+		{
+			int startnode = sc.nextInt();
+			int destnode = sc.nextInt();
+			int weight = sc.nextInt();
+		       	adj_list.get(startnode).add(new AdjListNode(destnode,weight));
+		}
+		int source;
+		System.out.println("Please enter source vertex");
+		source = sc.nextInt();
+		Dijkstras d = new Dijkstras();
+		int[] distances  = d.dijkstras(adj_list, source);  //source vertex is taken as 0
+		System.out.println("Distances from source "+source);
+		for(int i=0;i<distances.length;++i)
+		{
+			if(distances[i]==Integer.MAX_VALUE)
+				System.out.println("Node"+i+"--->"+"infinity");
+			else
+				System.out.println("Node"+i+"--->"+distances[i]);
+		}
+	}
+}

From ef836c94d07334dfb7d174f5d9b4582c4c2e0952 Mon Sep 17 00:00:00 2001
From: Toihir Halim <66559721+toihirhalim@users.noreply.github.com>
Date: Thu, 15 Apr 2021 02:37:29 +0200
Subject: [PATCH 05/11] Added string tokenizer in java (#184)

* Added string tokenizer in java

* fix typos

* Update Readme change line index from 4 to 5
---
 strings/README.md           |  1 +
 strings/java/tokenizer.java | 96 +++++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+)
 create mode 100644 strings/java/tokenizer.java

diff --git a/strings/README.md b/strings/README.md
index 07bb97dd..093af2aa 100644
--- a/strings/README.md
+++ b/strings/README.md
@@ -24,6 +24,7 @@
 2. [All subsequences](java/sequence.java)
 3. [KMP String Searching](java/kmp.cpp)
 4. [Rabin Karp String Searching](java/rabin-karp.cpp)
+5. [String Tokenizer](java/tokenizer.java)
 
 ### Python
 
diff --git a/strings/java/tokenizer.java b/strings/java/tokenizer.java
new file mode 100644
index 00000000..ce6c4dc6
--- /dev/null
+++ b/strings/java/tokenizer.java
@@ -0,0 +1,96 @@
+import java.util.ArrayList;
+import java.util.List;
+
+public class tokenizer{
+
+    public static boolean charIsDelimiter(char c, char [] delimiters){
+        //verrify if a character is a delimiter
+        for(char d: delimiters)
+            if(c == d) return true;
+        
+        return false;
+    }
+
+    public static List<String> tokenize(String str, char... delimiters){
+        //by default the delimiter is white space ' '
+        if(delimiters.length <= 0) delimiters = new char [] {' '};
+
+        List<String> tokens = new ArrayList<String>();
+		String token  = "";
+
+		for(int i = 0; i < str.length(); i++) {
+			char pos = str.charAt(i);
+
+			if(!charIsDelimiter(pos, delimiters)) {
+                //if the character is not a delimiter add it into the current token
+				token += pos;
+			}else {
+                //avoid an empty token before adding to the list
+				if(!token.equals(""))
+					tokens.add(token);
+				
+                token = "";
+			}
+		}
+
+        //add the last token to the list
+		tokens.add(token);
+
+		return tokens;
+    }
+
+    public static void printTokens(List<String> tokens){
+        if(tokens == null) return;
+
+        System.out.print("[ ");
+        for(String token : tokens){
+            System.out.print("'" + token + "', ");
+        }
+        System.out.println("]");
+    }
+
+    public static void main(String  [] args){
+        String myString = "Hello     I like pasta & pizza--hut";
+
+        System.out.println("myString = '" + myString + "'");
+
+        System.out.print("\ntokenize(myString) = ");
+        printTokens(tokenize(myString));
+
+        System.out.print("\ntokenize(myString, ' ', 'z') = ");
+        printTokens(tokenize(myString, ' ', 'z'));
+
+        System.out.print("\ntokenize(myString, 'p','l', 'u') = ");
+        printTokens(tokenize(myString, 'p','l', 'u'));
+
+        System.out.print("\ntokenize(myString, ' ', '&', '-') = ");
+        printTokens(tokenize(myString, ' ', '&', '-'));
+    }
+}
+
+/*
+    to call the function:
+        tokenize(str, delimiters)
+        str is a text
+        delimiters is a list of char which is by default white space : ' '
+        example: 
+            tokenize("hello world") = tokenize("hello world", ' ') = [ 'hello', 'world' ]
+            tokenize("hello world", ' ', 'l') = [ 'he', 'o', 'wor', 'd' ]
+
+
+    to run this file:
+        javac tokenizer.java
+        java tokenizer
+
+    result:
+        myString = 'Hello     I like pasta & pizza--hut'
+
+        tokenize(myString) = [ 'Hello', 'I', 'like', 'pasta', '&', 'pizza--hut', ]
+
+        tokenize(myString, ' ', 'z') = [ 'Hello', 'I', 'like', 'pasta', '&', 'pi', 'a--hut', ]
+
+        tokenize(myString, 'p','l', 'u') = [ 'He', 'o     I ', 'ike ', 'asta & ', 'izza--h', 't', ]
+
+        tokenize(myString, ' ', '&', '-') = [ 'Hello', 'I', 'like', 'pasta', 'pizza', 'hut', ]
+            
+*/

From 2f47d5c828cf078b65e9591a0ff20a50a106034f Mon Sep 17 00:00:00 2001
From: Ming Tsai <37890026+ming-tsai@users.noreply.github.com>
Date: Wed, 14 Apr 2021 21:42:45 -0400
Subject: [PATCH 06/11] chore: moving csharp file to its project (#198)

---
 algorithms/CSharp/.gitignore                  | 362 ++++++++++++++++++
 algorithms/CSharp/.vscode/launch.json         |  27 ++
 algorithms/CSharp/.vscode/tasks.json          |  42 ++
 algorithms/CSharp/CSharp.sln                  |  48 +++
 algorithms/CSharp/README.md                   |   9 +
 algorithms/CSharp/src/Algorithms.csproj       |   7 +
 algorithms/CSharp/src/Sorts/bubble-sort.cs    |  31 ++
 algorithms/CSharp/src/Sorts/insertion-sort.cs |  36 ++
 algorithms/CSharp/src/Sorts/selection-sort.cs |  40 ++
 algorithms/CSharp/src/Strings/palindrome.cs   |  28 ++
 .../CSharp/test/Algorithms.Tests.csproj       |  19 +
 algorithms/CSharp/test/Sorts/bubble-sort.cs   |  17 +
 .../CSharp/test/Sorts/insertion-sort.cs       |  17 +
 .../CSharp/test/Sorts/selection-sort.cs       |  17 +
 algorithms/CSharp/test/Strings/palindrome.cs  |  18 +
 sorting/README.md                             |   8 -
 sorting/csharp/bubble-sort.cs                 |  28 --
 sorting/csharp/insertion-sort.cs              |  33 --
 sorting/csharp/selection-sort.cs              |  37 --
 strings/README.md                             |   5 -
 strings/csharp/palindrome.cs                  |  24 --
 21 files changed, 718 insertions(+), 135 deletions(-)
 create mode 100644 algorithms/CSharp/.gitignore
 create mode 100644 algorithms/CSharp/.vscode/launch.json
 create mode 100644 algorithms/CSharp/.vscode/tasks.json
 create mode 100644 algorithms/CSharp/CSharp.sln
 create mode 100644 algorithms/CSharp/README.md
 create mode 100644 algorithms/CSharp/src/Algorithms.csproj
 create mode 100644 algorithms/CSharp/src/Sorts/bubble-sort.cs
 create mode 100644 algorithms/CSharp/src/Sorts/insertion-sort.cs
 create mode 100644 algorithms/CSharp/src/Sorts/selection-sort.cs
 create mode 100644 algorithms/CSharp/src/Strings/palindrome.cs
 create mode 100644 algorithms/CSharp/test/Algorithms.Tests.csproj
 create mode 100644 algorithms/CSharp/test/Sorts/bubble-sort.cs
 create mode 100644 algorithms/CSharp/test/Sorts/insertion-sort.cs
 create mode 100644 algorithms/CSharp/test/Sorts/selection-sort.cs
 create mode 100644 algorithms/CSharp/test/Strings/palindrome.cs
 delete mode 100644 sorting/csharp/bubble-sort.cs
 delete mode 100644 sorting/csharp/insertion-sort.cs
 delete mode 100644 sorting/csharp/selection-sort.cs
 delete mode 100644 strings/csharp/palindrome.cs

diff --git a/algorithms/CSharp/.gitignore b/algorithms/CSharp/.gitignore
new file mode 100644
index 00000000..3a8542dc
--- /dev/null
+++ b/algorithms/CSharp/.gitignore
@@ -0,0 +1,362 @@
+## Ignore Visual Studio temporary files, build results, and
+## files generated by popular Visual Studio add-ons.
+##
+## Get latest from https://github.com/github/gitignore/blob/master/VisualStudio.gitignore
+
+# User-specific files
+*.rsuser
+*.suo
+*.user
+*.userosscache
+*.sln.docstates
+
+# User-specific files (MonoDevelop/Xamarin Studio)
+*.userprefs
+
+# Mono auto generated files
+mono_crash.*
+
+# Build results
+[Dd]ebug/
+[Dd]ebugPublic/
+[Rr]elease/
+[Rr]eleases/
+x64/
+x86/
+[Ww][Ii][Nn]32/
+[Aa][Rr][Mm]/
+[Aa][Rr][Mm]64/
+bld/
+[Bb]in/
+[Oo]bj/
+[Ll]og/
+[Ll]ogs/
+
+# Visual Studio 2015/2017 cache/options directory
+.vs/
+# Uncomment if you have tasks that create the project's static files in wwwroot
+#wwwroot/
+
+# Visual Studio 2017 auto generated files
+Generated\ Files/
+
+# MSTest test Results
+[Tt]est[Rr]esult*/
+[Bb]uild[Ll]og.*
+
+# NUnit
+*.VisualState.xml
+TestResult.xml
+nunit-*.xml
+
+# Build Results of an ATL Project
+[Dd]ebugPS/
+[Rr]eleasePS/
+dlldata.c
+
+# Benchmark Results
+BenchmarkDotNet.Artifacts/
+
+# .NET Core
+project.lock.json
+project.fragment.lock.json
+artifacts/
+
+# ASP.NET Scaffolding
+ScaffoldingReadMe.txt
+
+# StyleCop
+StyleCopReport.xml
+
+# Files built by Visual Studio
+*_i.c
+*_p.c
+*_h.h
+*.ilk
+*.meta
+*.obj
+*.iobj
+*.pch
+*.pdb
+*.ipdb
+*.pgc
+*.pgd
+*.rsp
+*.sbr
+*.tlb
+*.tli
+*.tlh
+*.tmp
+*.tmp_proj
+*_wpftmp.csproj
+*.log
+*.vspscc
+*.vssscc
+.builds
+*.pidb
+*.svclog
+*.scc
+
+# Chutzpah Test files
+_Chutzpah*
+
+# Visual C++ cache files
+ipch/
+*.aps
+*.ncb
+*.opendb
+*.opensdf
+*.sdf
+*.cachefile
+*.VC.db
+*.VC.VC.opendb
+
+# Visual Studio profiler
+*.psess
+*.vsp
+*.vspx
+*.sap
+
+# Visual Studio Trace Files
+*.e2e
+
+# TFS 2012 Local Workspace
+$tf/
+
+# Guidance Automation Toolkit
+*.gpState
+
+# ReSharper is a .NET coding add-in
+_ReSharper*/
+*.[Rr]e[Ss]harper
+*.DotSettings.user
+
+# TeamCity is a build add-in
+_TeamCity*
+
+# DotCover is a Code Coverage Tool
+*.dotCover
+
+# AxoCover is a Code Coverage Tool
+.axoCover/*
+!.axoCover/settings.json
+
+# Coverlet is a free, cross platform Code Coverage Tool
+coverage*.json
+coverage*.xml
+coverage*.info
+
+# Visual Studio code coverage results
+*.coverage
+*.coveragexml
+
+# NCrunch
+_NCrunch_*
+.*crunch*.local.xml
+nCrunchTemp_*
+
+# MightyMoose
+*.mm.*
+AutoTest.Net/
+
+# Web workbench (sass)
+.sass-cache/
+
+# Installshield output folder
+[Ee]xpress/
+
+# DocProject is a documentation generator add-in
+DocProject/buildhelp/
+DocProject/Help/*.HxT
+DocProject/Help/*.HxC
+DocProject/Help/*.hhc
+DocProject/Help/*.hhk
+DocProject/Help/*.hhp
+DocProject/Help/Html2
+DocProject/Help/html
+
+# Click-Once directory
+publish/
+
+# Publish Web Output
+*.[Pp]ublish.xml
+*.azurePubxml
+# Note: Comment the next line if you want to checkin your web deploy settings,
+# but database connection strings (with potential passwords) will be unencrypted
+*.pubxml
+*.publishproj
+
+# Microsoft Azure Web App publish settings. Comment the next line if you want to
+# checkin your Azure Web App publish settings, but sensitive information contained
+# in these scripts will be unencrypted
+PublishScripts/
+
+# NuGet Packages
+*.nupkg
+# NuGet Symbol Packages
+*.snupkg
+# The packages folder can be ignored because of Package Restore
+**/[Pp]ackages/*
+# except build/, which is used as an MSBuild target.
+!**/[Pp]ackages/build/
+# Uncomment if necessary however generally it will be regenerated when needed
+#!**/[Pp]ackages/repositories.config
+# NuGet v3's project.json files produces more ignorable files
+*.nuget.props
+*.nuget.targets
+
+# Microsoft Azure Build Output
+csx/
+*.build.csdef
+
+# Microsoft Azure Emulator
+ecf/
+rcf/
+
+# Windows Store app package directories and files
+AppPackages/
+BundleArtifacts/
+Package.StoreAssociation.xml
+_pkginfo.txt
+*.appx
+*.appxbundle
+*.appxupload
+
+# Visual Studio cache files
+# files ending in .cache can be ignored
+*.[Cc]ache
+# but keep track of directories ending in .cache
+!?*.[Cc]ache/
+
+# Others
+ClientBin/
+~$*
+*~
+*.dbmdl
+*.dbproj.schemaview
+*.jfm
+*.pfx
+*.publishsettings
+orleans.codegen.cs
+
+# Including strong name files can present a security risk
+# (https://github.com/github/gitignore/pull/2483#issue-259490424)
+#*.snk
+
+# Since there are multiple workflows, uncomment next line to ignore bower_components
+# (https://github.com/github/gitignore/pull/1529#issuecomment-104372622)
+#bower_components/
+
+# RIA/Silverlight projects
+Generated_Code/
+
+# Backup & report files from converting an old project file
+# to a newer Visual Studio version. Backup files are not needed,
+# because we have git ;-)
+_UpgradeReport_Files/
+Backup*/
+UpgradeLog*.XML
+UpgradeLog*.htm
+ServiceFabricBackup/
+*.rptproj.bak
+
+# SQL Server files
+*.mdf
+*.ldf
+*.ndf
+
+# Business Intelligence projects
+*.rdl.data
+*.bim.layout
+*.bim_*.settings
+*.rptproj.rsuser
+*- [Bb]ackup.rdl
+*- [Bb]ackup ([0-9]).rdl
+*- [Bb]ackup ([0-9][0-9]).rdl
+
+# Microsoft Fakes
+FakesAssemblies/
+
+# GhostDoc plugin setting file
+*.GhostDoc.xml
+
+# Node.js Tools for Visual Studio
+.ntvs_analysis.dat
+node_modules/
+
+# Visual Studio 6 build log
+*.plg
+
+# Visual Studio 6 workspace options file
+*.opt
+
+# Visual Studio 6 auto-generated workspace file (contains which files were open etc.)
+*.vbw
+
+# Visual Studio LightSwitch build output
+**/*.HTMLClient/GeneratedArtifacts
+**/*.DesktopClient/GeneratedArtifacts
+**/*.DesktopClient/ModelManifest.xml
+**/*.Server/GeneratedArtifacts
+**/*.Server/ModelManifest.xml
+_Pvt_Extensions
+
+# Paket dependency manager
+.paket/paket.exe
+paket-files/
+
+# FAKE - F# Make
+.fake/
+
+# CodeRush personal settings
+.cr/personal
+
+# Python Tools for Visual Studio (PTVS)
+__pycache__/
+*.pyc
+
+# Cake - Uncomment if you are using it
+# tools/**
+# !tools/packages.config
+
+# Tabs Studio
+*.tss
+
+# Telerik's JustMock configuration file
+*.jmconfig
+
+# BizTalk build output
+*.btp.cs
+*.btm.cs
+*.odx.cs
+*.xsd.cs
+
+# OpenCover UI analysis results
+OpenCover/
+
+# Azure Stream Analytics local run output
+ASALocalRun/
+
+# MSBuild Binary and Structured Log
+*.binlog
+
+# NVidia Nsight GPU debugger configuration file
+*.nvuser
+
+# MFractors (Xamarin productivity tool) working folder
+.mfractor/
+
+# Local History for Visual Studio
+.localhistory/
+
+# BeatPulse healthcheck temp database
+healthchecksdb
+
+# Backup folder for Package Reference Convert tool in Visual Studio 2017
+MigrationBackup/
+
+# Ionide (cross platform F# VS Code tools) working folder
+.ionide/
+
+# Fody - auto-generated XML schema
+FodyWeavers.xsd
\ No newline at end of file
diff --git a/algorithms/CSharp/.vscode/launch.json b/algorithms/CSharp/.vscode/launch.json
new file mode 100644
index 00000000..15f08e94
--- /dev/null
+++ b/algorithms/CSharp/.vscode/launch.json
@@ -0,0 +1,27 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            // Use IntelliSense to find out which attributes exist for C# debugging
+            // Use hover for the description of the existing attributes
+            // For further information visit https://github.com/OmniSharp/omnisharp-vscode/blob/master/debugger-launchjson.md
+            "name": ".NET Core Launch (console)",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build",
+            // If you have changed target frameworks, make sure to update the program path.
+            "program": "${workspaceFolder}/test/bin/Debug/netcoreapp3.1/Algorithms.Tests.dll",
+            "args": [],
+            "cwd": "${workspaceFolder}/test",
+            // For more information about the 'console' field, see https://aka.ms/VSCode-CS-LaunchJson-Console
+            "console": "internalConsole",
+            "stopAtEntry": false
+        },
+        {
+            "name": ".NET Core Attach",
+            "type": "coreclr",
+            "request": "attach",
+            "processId": "${command:pickProcess}"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/.vscode/tasks.json b/algorithms/CSharp/.vscode/tasks.json
new file mode 100644
index 00000000..17a32f2e
--- /dev/null
+++ b/algorithms/CSharp/.vscode/tasks.json
@@ -0,0 +1,42 @@
+{
+    "version": "2.0.0",
+    "tasks": [
+        {
+            "label": "build",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "build",
+                "${workspaceFolder}/test/Algorithms.Tests.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        },
+        {
+            "label": "publish",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "publish",
+                "${workspaceFolder}/test/Algorithms.Tests.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        },
+        {
+            "label": "watch",
+            "command": "dotnet",
+            "type": "process",
+            "args": [
+                "watch",
+                "run",
+                "${workspaceFolder}/test/Algorithms.Tests.csproj",
+                "/property:GenerateFullPaths=true",
+                "/consoleloggerparameters:NoSummary"
+            ],
+            "problemMatcher": "$msCompile"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/CSharp.sln b/algorithms/CSharp/CSharp.sln
new file mode 100644
index 00000000..b1f09671
--- /dev/null
+++ b/algorithms/CSharp/CSharp.sln
@@ -0,0 +1,48 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+VisualStudioVersion = 15.0.26124.0
+MinimumVisualStudioVersion = 15.0.26124.0
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Algorithms", "src\Algorithms.csproj", "{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Algorithms.Tests", "test\Algorithms.Tests.csproj", "{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|Any CPU = Release|Any CPU
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Debug|x64.Build.0 = Debug|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Debug|x86.Build.0 = Debug|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Release|x64.ActiveCfg = Release|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Release|x64.Build.0 = Release|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Release|x86.ActiveCfg = Release|Any CPU
+		{EDD3C753-58A5-4844-81EA-3E9BD6A1D2F6}.Release|x86.Build.0 = Release|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Debug|x64.Build.0 = Debug|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Debug|x86.Build.0 = Debug|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Release|x64.ActiveCfg = Release|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Release|x64.Build.0 = Release|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Release|x86.ActiveCfg = Release|Any CPU
+		{8E5D96D1-0618-4A33-9AF6-95D1D8F14E5A}.Release|x86.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal
diff --git a/algorithms/CSharp/README.md b/algorithms/CSharp/README.md
new file mode 100644
index 00000000..43795628
--- /dev/null
+++ b/algorithms/CSharp/README.md
@@ -0,0 +1,9 @@
+# C#
+## Strings
+- [Palindrome](src/Strings/palindrome.cs)
+
+## Sorts
+
+1. [Bubble Sort](src/Sorts/bubble-sort.cs)
+2. [Insertion Sort](src/Sorts/insertion-sort.cs)
+3. [Selection Sort](src/Sorts/selection-sort.cs)
\ No newline at end of file
diff --git a/algorithms/CSharp/src/Algorithms.csproj b/algorithms/CSharp/src/Algorithms.csproj
new file mode 100644
index 00000000..cb631906
--- /dev/null
+++ b/algorithms/CSharp/src/Algorithms.csproj
@@ -0,0 +1,7 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+  </PropertyGroup>
+
+</Project>
diff --git a/algorithms/CSharp/src/Sorts/bubble-sort.cs b/algorithms/CSharp/src/Sorts/bubble-sort.cs
new file mode 100644
index 00000000..b16248fb
--- /dev/null
+++ b/algorithms/CSharp/src/Sorts/bubble-sort.cs
@@ -0,0 +1,31 @@
+using System;
+
+namespace Algorithms.Sorts
+{
+    public class BubbleSort
+    {
+        public static void Main()
+        {
+            int[] arr = { 800, 11, 50, 771, 649, 770, 240, 9 };
+            Sort(arr);
+            var result = string.Join(" ", arr);
+            Console.WriteLine(result);
+        }
+
+        public static void Sort(int[] source)
+        {
+            for (int write = 0; write < source.Length; write++)
+            {
+                for (int sort = 0; sort < source.Length - 1; sort++)
+                {
+                    if (source[sort] > source[sort + 1])
+                    {
+                        var temp = source[sort + 1];
+                        source[sort + 1] = source[sort];
+                        source[sort] = temp;
+                    }
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/src/Sorts/insertion-sort.cs b/algorithms/CSharp/src/Sorts/insertion-sort.cs
new file mode 100644
index 00000000..c7c14982
--- /dev/null
+++ b/algorithms/CSharp/src/Sorts/insertion-sort.cs
@@ -0,0 +1,36 @@
+using System;
+
+namespace Algorithms.Sorts
+{
+    public class InsertionSort
+    {
+        public static void Main()
+        {
+            int[] arr = { 800, 11, 50, 771, 649, 770, 240, 9 };
+            Sort(arr);
+            var result = string.Join(" ", arr);
+            Console.WriteLine(result);
+        }
+
+        public static void Sort(int[] source)
+        {
+            int n = source.Length;
+            for (int i = 1; i < n; ++i)
+            {
+                int key = source[i];
+                int j = i - 1;
+
+                // Move elements of arr[0..i-1], 
+                // that are greater than key, 
+                // to one position ahead of 
+                // their current position 
+                while (j >= 0 && source[j] > key)
+                {
+                    source[j + 1] = source[j];
+                    j = j - 1;
+                }
+                source[j + 1] = key;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/src/Sorts/selection-sort.cs b/algorithms/CSharp/src/Sorts/selection-sort.cs
new file mode 100644
index 00000000..6dd53654
--- /dev/null
+++ b/algorithms/CSharp/src/Sorts/selection-sort.cs
@@ -0,0 +1,40 @@
+using System;
+
+namespace Algorithms.Sorts
+{
+    public class SelectionSort
+    {
+        public static void Main()
+        {
+            int[] arr = { 800, 11, 50, 771, 649, 770, 240, 9 };
+            Sort(arr);
+            var result = string.Join(" ", arr);
+            Console.WriteLine(result);
+        }
+
+        public static void Sort(int[] source)
+        {
+            int n = source.Length;
+
+            // One by one move boundary of unsorted subarray 
+            for (int i = 0; i < n - 1; i++)
+            {
+                // Find the minimum element in unsorted array 
+                int min_idx = i;
+                for (int j = i + 1; j < n; j++)
+                {
+                    if (source[j] < source[min_idx])
+                    {
+                        min_idx = j;
+                    }
+                }
+
+                // Swap the found minimum element with the first 
+                // element 
+                int temp = source[min_idx];
+                source[min_idx] = source[i];
+                source[i] = temp;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/src/Strings/palindrome.cs b/algorithms/CSharp/src/Strings/palindrome.cs
new file mode 100644
index 00000000..3c30ad33
--- /dev/null
+++ b/algorithms/CSharp/src/Strings/palindrome.cs
@@ -0,0 +1,28 @@
+using System;
+using System.Linq;
+using System.Text.RegularExpressions;
+
+namespace Algorithms.Strings
+{
+    public class Palindrome
+    {
+        public static void Main()
+        {
+            bool result = false;
+            result = IsPalindrome("abba");
+            Console.WriteLine(result);
+            result = IsPalindrome("abbccbbA");
+            Console.WriteLine(result);
+            result = IsPalindrome("Mr. Owl ate my metal worm");
+            Console.WriteLine(result);
+        }
+
+        public static bool IsPalindrome(string source)
+        {
+            source = source.ToLower();
+            source = Regex.Replace(source, @"[^0-9A-Za-z]", "");
+            string reverse = new string(Enumerable.Range(1, source.Length).Select(i => source[source.Length - i]).ToArray());
+            return reverse == source;
+        }
+    }
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/test/Algorithms.Tests.csproj b/algorithms/CSharp/test/Algorithms.Tests.csproj
new file mode 100644
index 00000000..e26afb5b
--- /dev/null
+++ b/algorithms/CSharp/test/Algorithms.Tests.csproj
@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="NUnit" Version="3.12.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="3.16.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.5.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\src\Algorithms.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/algorithms/CSharp/test/Sorts/bubble-sort.cs b/algorithms/CSharp/test/Sorts/bubble-sort.cs
new file mode 100644
index 00000000..4da77fc1
--- /dev/null
+++ b/algorithms/CSharp/test/Sorts/bubble-sort.cs
@@ -0,0 +1,17 @@
+using NUnit.Framework;
+
+namespace algorithms.CSharp.Test.Sorts
+{
+    [TestFixture]
+    internal class BubbleSort
+    {
+        [Test]
+        public void SortTheArray_ShouldGetExpectedString()
+        {
+            int[] array = { 800, 11, 50, 771, 649, 770, 240, 9 };
+            Algorithms.Sorts.BubbleSort.Sort(array);
+            var result = string.Join(" ", array);
+            Assert.AreEqual("9 11 50 240 649 770 771 800", result);
+        }
+    }
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/test/Sorts/insertion-sort.cs b/algorithms/CSharp/test/Sorts/insertion-sort.cs
new file mode 100644
index 00000000..f8f8fa9c
--- /dev/null
+++ b/algorithms/CSharp/test/Sorts/insertion-sort.cs
@@ -0,0 +1,17 @@
+using NUnit.Framework;
+
+namespace algorithms.CSharp.Test.Sorts
+{
+    [TestFixture]
+    internal class InsertionSort
+    {
+        [Test]
+        public void SortTheArray_ShouldGetExpectedString()
+        {
+            int[] array = { 800, 11, 50, 771, 649, 770, 240, 9 };
+            Algorithms.Sorts.InsertionSort.Sort(array);
+            var result = string.Join(" ", array);
+            Assert.AreEqual("9 11 50 240 649 770 771 800", result);
+        }
+    }
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/test/Sorts/selection-sort.cs b/algorithms/CSharp/test/Sorts/selection-sort.cs
new file mode 100644
index 00000000..5cb558b6
--- /dev/null
+++ b/algorithms/CSharp/test/Sorts/selection-sort.cs
@@ -0,0 +1,17 @@
+using NUnit.Framework;
+
+namespace algorithms.CSharp.Test.Sorts
+{
+    [TestFixture]
+    internal class SelectionSort
+    {
+        [Test]
+        public void SortTheArray_ShouldGetExpectedString()
+        {
+            int[] array = { 800, 11, 50, 771, 649, 770, 240, 9 };
+            Algorithms.Sorts.SelectionSort.Sort(array);
+            var result = string.Join(" ", array);
+            Assert.AreEqual("9 11 50 240 649 770 771 800", result);
+        }
+    }
+}
\ No newline at end of file
diff --git a/algorithms/CSharp/test/Strings/palindrome.cs b/algorithms/CSharp/test/Strings/palindrome.cs
new file mode 100644
index 00000000..800074ee
--- /dev/null
+++ b/algorithms/CSharp/test/Strings/palindrome.cs
@@ -0,0 +1,18 @@
+using NUnit.Framework;
+
+namespace Algorithms.CSharp.Test.Strings
+{
+    [TestFixture]
+    internal class Palindrome
+    {
+        [TestCase("abba", true)]
+        [TestCase("abbccbbA", true)]
+        [TestCase("Mr. Owl ate my metal worm", true)]
+        [TestCase("asdfgasdfg", false)]
+        public void PassString_ShouldGetExpectedResult(string text, bool expected)
+        {
+            var result = Algorithms.Strings.Palindrome.IsPalindrome(text);
+            Assert.AreEqual(expected, result);
+        }
+    }
+}
\ No newline at end of file
diff --git a/sorting/README.md b/sorting/README.md
index 63a1761f..8d53fc78 100644
--- a/sorting/README.md
+++ b/sorting/README.md
@@ -15,14 +15,6 @@
 11. [Comb Sort](c-or-cpp/comb-sort.cpp)
 12. [3 Way Quick Sort](c-or-cpp/3way_quick_sort.cpp)
 
-
-
-### C#
-
-1. [Bubble Sort](csharp/bubble-sort.cs)
-2. [Insertion Sort](csharp/insertion-sort.cs)
-3. [Selection Sort](csharp/selection-sort.cs)
-
 ### Python
 
 1. [Bubble Sort](python/bubble-sort.py)
diff --git a/sorting/csharp/bubble-sort.cs b/sorting/csharp/bubble-sort.cs
deleted file mode 100644
index 7346933c..00000000
--- a/sorting/csharp/bubble-sort.cs
+++ /dev/null
@@ -1,28 +0,0 @@
-using System;
-
-public class Program
-{
-    public static void Main()
-    {
-        int[] arr = { 800, 11, 50, 771, 649, 770, 240, 9 };
-        Sort(arr);
-        var result = string.Join(" ", arr);
-        Console.WriteLine(result);
-    }
-    
-    public static void Sort(int[] source)
-    {
-        for (int write = 0; write < source.Length; write++)
-        {
-            for (int sort = 0; sort < source.Length - 1; sort++)
-            {
-                if (source[sort] > source[sort + 1])
-                {
-                    var temp = source[sort + 1];
-                    source[sort + 1] = source[sort];
-                    source[sort] = temp;
-                }
-            }
-        }
-    }
-}
\ No newline at end of file
diff --git a/sorting/csharp/insertion-sort.cs b/sorting/csharp/insertion-sort.cs
deleted file mode 100644
index 02e4184f..00000000
--- a/sorting/csharp/insertion-sort.cs
+++ /dev/null
@@ -1,33 +0,0 @@
-using System;
-
-public class Program
-{
-    public static void Main()
-    {
-        int[] arr = { 800, 11, 50, 771, 649, 770, 240, 9 };
-        Sort(arr);
-        var result = string.Join(" ", arr);
-        Console.WriteLine(result);
-    }
-    
-    private static void Sort(int[] source) 
-    { 
-        int n = source.Length;
-        for (int i = 1; i < n; ++i)
-        {
-            int key = source[i];
-            int j = i - 1;
-
-            // Move elements of arr[0..i-1], 
-            // that are greater than key, 
-            // to one position ahead of 
-            // their current position 
-            while (j >= 0 && source[j] > key)
-            {
-                source[j + 1] = source[j];
-                j = j - 1;
-            }
-            source[j + 1] = key;
-        }
-    } 
-}
\ No newline at end of file
diff --git a/sorting/csharp/selection-sort.cs b/sorting/csharp/selection-sort.cs
deleted file mode 100644
index 8a44bac9..00000000
--- a/sorting/csharp/selection-sort.cs
+++ /dev/null
@@ -1,37 +0,0 @@
-using System;
-
-public class Program
-{
-    public static void Main()
-    {
-        int[] arr = { 800, 11, 50, 771, 649, 770, 240, 9 };
-        Sort(arr);
-        var result = string.Join(" ", arr);
-        Console.WriteLine(result);
-    }
-
-    private static void Sort(int[] source)
-    {
-        int n = source.Length;
-
-        // One by one move boundary of unsorted subarray 
-        for (int i = 0; i < n - 1; i++)
-        {
-            // Find the minimum element in unsorted array 
-            int min_idx = i;
-            for (int j = i + 1; j < n; j++)
-            {
-                if (source[j] < source[min_idx])
-                {
-                    min_idx = j;
-                }
-            }
-
-            // Swap the found minimum element with the first 
-            // element 
-            int temp = source[min_idx];
-            source[min_idx] = source[i];
-            source[i] = temp;
-        }
-    }
-}
\ No newline at end of file
diff --git a/strings/README.md b/strings/README.md
index 093af2aa..db502f05 100644
--- a/strings/README.md
+++ b/strings/README.md
@@ -9,11 +9,6 @@
 5. [String Tokeniser](c-or-cpp/string-tokeniser.cpp)
 6. [String Reversal](c-or-cpp/string-reverse.cpp)
 7. [Permutation of String](c-or-cpp/Permutation-of-String.c)
-
-### C#
-
-1. [Palindrome Check](csharp/palindrome.cs)
-
 ### JavaScript
 
 1. [Palindrome Check](js/palindrome.js)
diff --git a/strings/csharp/palindrome.cs b/strings/csharp/palindrome.cs
deleted file mode 100644
index b01d70cb..00000000
--- a/strings/csharp/palindrome.cs
+++ /dev/null
@@ -1,24 +0,0 @@
-using System;
-using System.Linq;
-using System.Text.RegularExpressions;
-                    
-public class Program
-{
-    public static void Main()
-    {
-        bool result = false;
-        result = IsPalindrome("abba");
-        Console.WriteLine(result);
-        result = IsPalindrome("abbccbbA");
-        Console.WriteLine(result);
-        result = IsPalindrome("Mr. Owl ate my metal worm");
-        Console.WriteLine(result);
-    }
-    
-    private static bool IsPalindrome(string source) {
-        source = source.ToLower();
-        source = Regex.Replace(source, @"[^0-9A-Za-z]", "");
-        string reverse = new string(Enumerable.Range(1, source.Length).Select(i => source[source.Length - i]).ToArray());
-        return reverse == source;
-    }
-}
\ No newline at end of file

From 9d35a9e42cf61a706f00f67aff389e38a8f3858b Mon Sep 17 00:00:00 2001
From: Ming Tsai <37890026+ming-tsai@users.noreply.github.com>
Date: Wed, 14 Apr 2021 21:44:45 -0400
Subject: [PATCH 07/11] chore: add dotnet action

---
 .github/workflows/dotnet.yml | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 .github/workflows/dotnet.yml

diff --git a/.github/workflows/dotnet.yml b/.github/workflows/dotnet.yml
new file mode 100644
index 00000000..6b6e1f79
--- /dev/null
+++ b/.github/workflows/dotnet.yml
@@ -0,0 +1,27 @@
+name: .NET
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 3.1.x
+    - name: Go to directory
+      run: cd 'algorithms/CSharp'
+    - name: Restore dependencies
+      run: dotnet restore
+    - name: Build
+      run: dotnet build --no-restore
+    - name: Test
+      run: dotnet test --no-build --verbosity normal

From f62e6f7281487945efc669c419b58f76197c8bdc Mon Sep 17 00:00:00 2001
From: Ming Tsai <37890026+ming-tsai@users.noreply.github.com>
Date: Wed, 14 Apr 2021 21:45:49 -0400
Subject: [PATCH 08/11] fix: the cd path

---
 .github/workflows/dotnet.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/dotnet.yml b/.github/workflows/dotnet.yml
index 6b6e1f79..a86a1bdc 100644
--- a/.github/workflows/dotnet.yml
+++ b/.github/workflows/dotnet.yml
@@ -18,7 +18,7 @@ jobs:
       with:
         dotnet-version: 3.1.x
     - name: Go to directory
-      run: cd 'algorithms/CSharp'
+      run: cd algorithms/CSharp
     - name: Restore dependencies
       run: dotnet restore
     - name: Build

From e9c25476d67acfa795caa6135239784558aa8266 Mon Sep 17 00:00:00 2001
From: Ming Tsai <37890026+ming-tsai@users.noreply.github.com>
Date: Wed, 14 Apr 2021 21:50:45 -0400
Subject: [PATCH 09/11] chore: list the directory

---
 .github/workflows/dotnet.yml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/dotnet.yml b/.github/workflows/dotnet.yml
index a86a1bdc..5fc9be8c 100644
--- a/.github/workflows/dotnet.yml
+++ b/.github/workflows/dotnet.yml
@@ -18,7 +18,9 @@ jobs:
       with:
         dotnet-version: 3.1.x
     - name: Go to directory
-      run: cd algorithms/CSharp
+      run: |
+        cd algorithms/CSharp
+        ls
     - name: Restore dependencies
       run: dotnet restore
     - name: Build

From ed658ec53db18ba00e006a54daf63a138911b59d Mon Sep 17 00:00:00 2001
From: Ming Tsai <37890026+ming-tsai@users.noreply.github.com>
Date: Wed, 14 Apr 2021 21:53:40 -0400
Subject: [PATCH 10/11] chore: list the folder before run dotnet test

---
 .github/workflows/dotnet.yml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/dotnet.yml b/.github/workflows/dotnet.yml
index 5fc9be8c..cb627e4c 100644
--- a/.github/workflows/dotnet.yml
+++ b/.github/workflows/dotnet.yml
@@ -22,7 +22,9 @@ jobs:
         cd algorithms/CSharp
         ls
     - name: Restore dependencies
-      run: dotnet restore
+      run: |
+        ls
+        dotnet restore
     - name: Build
       run: dotnet build --no-restore
     - name: Test

From 92e336fcaecfc105810f77e2a29b1a545bdb2273 Mon Sep 17 00:00:00 2001
From: Ming Tsai <ming.jia1213@gmail.com>
Date: Wed, 14 Apr 2021 21:57:01 -0400
Subject: [PATCH 11/11] chore: add path on restore, build and test

---
 .github/workflows/dotnet.yml                     | 12 +++---------
 algorithms/CSharp/{CSharp.sln => Algorithms.sln} |  0
 2 files changed, 3 insertions(+), 9 deletions(-)
 rename algorithms/CSharp/{CSharp.sln => Algorithms.sln} (100%)

diff --git a/.github/workflows/dotnet.yml b/.github/workflows/dotnet.yml
index cb627e4c..2414ed29 100644
--- a/.github/workflows/dotnet.yml
+++ b/.github/workflows/dotnet.yml
@@ -17,15 +17,9 @@ jobs:
       uses: actions/setup-dotnet@v1
       with:
         dotnet-version: 3.1.x
-    - name: Go to directory
-      run: |
-        cd algorithms/CSharp
-        ls
     - name: Restore dependencies
-      run: |
-        ls
-        dotnet restore
+      run: dotnet restore algorithms/CSharp
     - name: Build
-      run: dotnet build --no-restore
+      run: dotnet build algorithms/CSharp --no-restore
     - name: Test
-      run: dotnet test --no-build --verbosity normal
+      run: dotnet test algorithms/CSharp --no-build --verbosity normal
diff --git a/algorithms/CSharp/CSharp.sln b/algorithms/CSharp/Algorithms.sln
similarity index 100%
rename from algorithms/CSharp/CSharp.sln
rename to algorithms/CSharp/Algorithms.sln