done

pom.xml

@@ -7,6 +7,14 @@
     <groupId>com.zipcodewilmington</groupId>
     <artifactId>singlylinkedlist</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.1</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
 
 
 </project>

src/main/java/com/zipcodewilmington/singlylinkedlist/SinglyLinkedList.java

@@ -1,7 +1,127 @@
 package com.zipcodewilmington.singlylinkedlist;
 
+import com.sun.org.apache.xpath.internal.operations.Bool;
+
 /**
  * Created by leon on 1/10/18.
  */
 public class SinglyLinkedList {
+
+    class Node {
+        Object data;
+        Node next;
+
+        public Node(Object data){
+            this.data = data;
+            next = null;
+        }
+    }
+
+    public Node head;
+    public Node tail;
+
+    public void add(Object data){
+        Node newNode = new Node(data);
+        if(this.head == null){
+            this.head = newNode;
+        } else {
+            tail.next = newNode;
+        }
+        tail = newNode;
+    }
+
+    public void remove(int index){
+        Node current = this.head;
+        Node previous = null;
+
+        if (index == 0 && current != null){
+            this.head = current.next;
+        }
+        int counter = 0;
+        while (current != null) {
+            if(counter == index){
+                previous.next = current.next; //[previous] -> [current.next]
+                break;
+            } else {
+                previous = current;
+                current = current.next;
+                counter++;
+            }
+        }
+        if (current == null){
+            System.out.println("not found");
+        }
+    }
+
+    public Boolean contains(Object key){
+        Node current = this.head;
+        while (current != null) {
+            if (current.data == key){
+                return true;
+            }
+            current = current.next;
+        }
+        return  false;
+    }
+
+    public int size(){
+        int counter = 0;
+        Node current = head;
+        while (current != null) {
+            counter++;
+            current = current.next;
+        }
+        return counter;
+    }
+
+    public Integer find(int data){
+        Node current = this.head;
+        int index = 0;
+        while(current != null){
+            if(current.data.equals(data)){
+                return  index;
+            }
+            index++;
+            current = current.next;
+        }
+        return -1;
+    }
+
+    public Object get(int index){
+        Node current = this.head;
+        int seek = 0;
+        while(current != null){
+            if(seek == index){
+                return current.data;
+            }
+            seek++;
+            current = current.next;
+        }
+        return -1;
+    }
+
+    public SinglyLinkedList copy(){
+        SinglyLinkedList copiedList = new SinglyLinkedList();
+        Node current = this.head;
+        while(current != null){
+            copiedList.add(current.data);
+            current = current.next;
+        }
+        return  copiedList;
+    }
+
+    public void sort(){
+        Node current = this.head;
+        for(int i =0; i < size(); i++){
+            while(current.next != null){
+                Node next = current.next;
+                if((Integer)current.data > (Integer) next.data){ // [head] -> [current] -> current.next] -> [tail] -> [null]
+                    Object temp = current.data;
+                    current.data = next.data;
+                    next.data = temp;
+                }
+                current = current.next;
+            }
+        }
+    }
 }

src/test/java/com/zipcodewilmington/singlylinkedlist/SinglyLinkedListTest.java

@@ -1,7 +1,167 @@
 package com.zipcodewilmington.singlylinkedlist;
 
+import com.sun.org.apache.xpath.internal.operations.Bool;
+import org.junit.Assert;
+import org.junit.Test;
+
 /**
  * Created by leon on 1/10/18.
  */
 public class SinglyLinkedListTest {
+
+    @Test
+    public void addTest(){
+        // Given
+        SinglyLinkedList list = new SinglyLinkedList();
+
+        // When
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(4);
+
+        int actual = list.size();
+        int expected = 4;
+
+
+        // Then
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void removeTest(){
+        // Given
+        SinglyLinkedList list = new SinglyLinkedList();
+
+        // When
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(4);
+
+       list.remove(3);
+       int expected = 3;
+       int actual = list.size();
+
+       Assert.assertEquals(expected, actual);
+
+    }
+
+    @Test
+    public void containsTest(){
+        // Given
+        SinglyLinkedList list = new SinglyLinkedList();
+
+        // When
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(4);
+
+        Boolean actual = list.contains(3);
+
+        Assert.assertTrue(actual);
+        Assert.assertFalse(list.contains(6));
+    }
+
+    @Test
+    public void sizeTest(){
+        // Given
+        SinglyLinkedList list = new SinglyLinkedList();
+
+        // When
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(4);
+        list.add(5);
+        list.add(6);
+
+        int expected = 6;
+        int actual =list.size();
+
+        Assert.assertEquals(expected,actual);
+    }
+
+    @Test
+    public void findTest(){
+        // Given
+        SinglyLinkedList list = new SinglyLinkedList();
+
+        // When
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(4);
+        list.add(5);
+        list.add(6);
+
+        Integer actual = list.find(4);
+        Integer expected = 3;
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void getTest(){
+        // Given
+        SinglyLinkedList list = new SinglyLinkedList();
+
+        // When
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(4);
+        list.add(5);
+        list.add(6);
+
+        Integer actual = (Integer) list.get(4);
+        Integer expected = 5;
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void copyTest(){
+        // Given
+        SinglyLinkedList list = new SinglyLinkedList();
+
+        // When
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(4);
+        list.add(5);
+        list.add(6);
+
+        SinglyLinkedList newList = list.copy();
+        Integer expected = list.size();
+        Integer actual = newList.size();
+
+        Assert.assertEquals(expected, actual);
+
+    }
+
+    @Test
+    public void sortTest(){
+        // Given
+        SinglyLinkedList list = new SinglyLinkedList();
+
+        // When
+        list.add(1);
+        list.add(2);
+        list.add(3);
+        list.add(4);
+        list.add(5);
+        list.add(9);
+        list.add(7);
+        list.add(6);
+
+        list.sort();
+
+        Assert.assertTrue(list.find(1) == 0);
+        Assert.assertTrue(list.find(9) == 7);
+
+    }
+
 }