diff --git a/02. Linked lists/hackerrank/delete_duplicate_nodes.java b/02. Linked lists/hackerrank/delete_duplicate_nodes.java
new file mode 100644
index 0000000..7cc789a
--- /dev/null
+++ b/02. Linked lists/hackerrank/delete_duplicate_nodes.java	
@@ -0,0 +1,106 @@
+import java.io.*;
+import java.math.*;
+import java.security.*;
+import java.text.*;
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.regex.*;
+
+public class Solution {
+
+    static class SinglyLinkedListNode {
+        public int data;
+        public SinglyLinkedListNode next;
+
+        public SinglyLinkedListNode(int nodeData) {
+            this.data = nodeData;
+            this.next = null;
+        }
+    }
+
+    static class SinglyLinkedList {
+        public SinglyLinkedListNode head;
+        public SinglyLinkedListNode tail;
+
+        public SinglyLinkedList() {
+            this.head = null;
+            this.tail = null;
+        }
+
+        public void insertNode(int nodeData) {
+            SinglyLinkedListNode node = new SinglyLinkedListNode(nodeData);
+
+            if (this.head == null) {
+                this.head = node;
+            } else {
+                this.tail.next = node;
+            }
+
+            this.tail = node;
+        }
+    }
+
+    public static void printSinglyLinkedList(SinglyLinkedListNode node, String sep, BufferedWriter bufferedWriter)
+            throws IOException {
+        while (node != null) {
+            bufferedWriter.write(String.valueOf(node.data));
+
+            node = node.next;
+
+            if (node != null) {
+                bufferedWriter.write(sep);
+            }
+        }
+    }
+
+    // Complete the removeDuplicates function below.
+
+    /*
+     * For your reference:
+     *
+     * SinglyLinkedListNode { int data; SinglyLinkedListNode next; }
+     *
+     */
+    static SinglyLinkedListNode removeDuplicates(SinglyLinkedListNode head) {
+        SinglyLinkedListNode head_copy = head;
+        while (head.next != null) {
+            if (head.data == head.next.data) {
+                if (head.next.next == null) head.next = null;
+                elsehead.next = head.next.next;
+            } else head = head.next;
+        }
+        return head_copy;
+    }
+
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) throws IOException {
+        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
+
+        int t = scanner.nextInt();
+        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+        for (int tItr = 0; tItr < t; tItr++) {
+            SinglyLinkedList llist = new SinglyLinkedList();
+
+            int llistCount = scanner.nextInt();
+            scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+            for (int i = 0; i < llistCount; i++) {
+                int llistItem = scanner.nextInt();
+                scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+                llist.insertNode(llistItem);
+            }
+
+            SinglyLinkedListNode llist1 = removeDuplicates(llist.head);
+
+            printSinglyLinkedList(llist1, " ", bufferedWriter);
+            bufferedWriter.newLine();
+        }
+
+        bufferedWriter.close();
+
+        scanner.close();
+    }
+}
diff --git a/02. Linked lists/hackerrank/merge_sorted_lists.java b/02. Linked lists/hackerrank/merge_sorted_lists.java
new file mode 100644
index 0000000..62a3321
--- /dev/null
+++ b/02. Linked lists/hackerrank/merge_sorted_lists.java	
@@ -0,0 +1,122 @@
+import java.io.*;
+import java.math.*;
+import java.security.*;
+import java.text.*;
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.regex.*;
+
+public class Solution {
+
+    static class SinglyLinkedListNode {
+        public int data;
+        public SinglyLinkedListNode next;
+
+        public SinglyLinkedListNode(int nodeData) {
+            this.data = nodeData;
+            this.next = null;
+        }
+    }
+
+    static class SinglyLinkedList {
+        public SinglyLinkedListNode head;
+        public SinglyLinkedListNode tail;
+
+        public SinglyLinkedList() {
+            this.head = null;
+            this.tail = null;
+        }
+
+        public void insertNode(int nodeData) {
+            SinglyLinkedListNode node = new SinglyLinkedListNode(nodeData);
+
+            if (this.head == null) {
+                this.head = node;
+            } else {
+                this.tail.next = node;
+            }
+
+            this.tail = node;
+        }
+    }
+
+    public static void printSinglyLinkedList(SinglyLinkedListNode node, String sep, BufferedWriter bufferedWriter)
+            throws IOException {
+        while (node != null) {
+            bufferedWriter.write(String.valueOf(node.data));
+
+            node = node.next;
+
+            if (node != null) {
+                bufferedWriter.write(sep);
+            }
+        }
+    }
+
+    // Complete the mergeLists function below.
+
+    /*
+     * For your reference:
+     *
+     * SinglyLinkedListNode { int data; SinglyLinkedListNode next; }
+     *
+     */
+    static SinglyLinkedListNode mergeLists(SinglyLinkedListNode head1, SinglyLinkedListNode head2) {
+        if (head1 == null)
+            return head2;
+        else if (head2 == null)
+            return head1;
+
+        if (head1.data < head2.data) {
+            head1.next = mergeLists(head1.next, head2);
+            return head1;
+        } else {
+            head2.next = mergeLists(head1, head2.next);
+            return head2;
+        }
+    }
+
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) throws IOException {
+        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
+
+        int tests = scanner.nextInt();
+        scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+        for (int testsItr = 0; testsItr < tests; testsItr++) {
+            SinglyLinkedList llist1 = new SinglyLinkedList();
+
+            int llist1Count = scanner.nextInt();
+            scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+            for (int i = 0; i < llist1Count; i++) {
+                int llist1Item = scanner.nextInt();
+                scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+                llist1.insertNode(llist1Item);
+            }
+
+            SinglyLinkedList llist2 = new SinglyLinkedList();
+
+            int llist2Count = scanner.nextInt();
+            scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+            for (int i = 0; i < llist2Count; i++) {
+                int llist2Item = scanner.nextInt();
+                scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
+
+                llist2.insertNode(llist2Item);
+            }
+
+            SinglyLinkedListNode llist3 = mergeLists(llist1.head, llist2.head);
+
+            printSinglyLinkedList(llist3, " ", bufferedWriter);
+            bufferedWriter.newLine();
+        }
+
+        bufferedWriter.close();
+
+        scanner.close();
+    }
+}