From 5033bd5c451febf137493063a6a68c6925aef090 Mon Sep 17 00:00:00 2001
From: Medha Sunkad <medhasunkad13@gmail.com>
Date: Sun, 19 Oct 2025 18:20:20 +0530
Subject: [PATCH 1/2] Added FindMiddleNode, FindMiddleNodeTest, ListNode, and
 corresponding JUnit test

---
 .../datastructures/lists/FindMiddleNode.java  | 27 +++++++++++++++++
 .../datastructures/lists/ListNode.java        | 11 +++++++
 .../lists/FindMiddleNodeTest.java             | 30 +++++++++++++++++++
 3 files changed, 68 insertions(+)
 create mode 100644 src/main/java/com/thealgorithms/datastructures/lists/FindMiddleNode.java
 create mode 100644 src/main/java/com/thealgorithms/datastructures/lists/ListNode.java
 create mode 100644 src/test/java/com/thealgorithms/datastructures/lists/FindMiddleNodeTest.java

diff --git a/src/main/java/com/thealgorithms/datastructures/lists/FindMiddleNode.java b/src/main/java/com/thealgorithms/datastructures/lists/FindMiddleNode.java
new file mode 100644
index 000000000000..00e403c23c47
--- /dev/null
+++ b/src/main/java/com/thealgorithms/datastructures/lists/FindMiddleNode.java
@@ -0,0 +1,27 @@
+package com.thealgorithms.datastructures.lists;
+
+public class FindMiddleNode {
+
+    public static ListNode findMiddle(ListNode head) {
+        ListNode slow = head;
+        ListNode fast = head;
+        while (fast != null && fast.next != null) {
+            slow = slow.next;
+            fast = fast.next.next;
+        }
+        return slow;
+    }
+
+    public static void main(String[] args) {
+        // Example: create a linked list 1->2->3->4->5
+        ListNode head = new ListNode(1);
+        head.next = new ListNode(2);
+        head.next.next = new ListNode(3);
+        head.next.next.next = new ListNode(4);
+        head.next.next.next.next = new ListNode(5);
+
+        ListNode middle = findMiddle(head);
+        System.out.println("Middle node value: " + middle.value);
+    }
+}
+// package com.thealgorithms.datastructures.lists;
\ No newline at end of file
diff --git a/src/main/java/com/thealgorithms/datastructures/lists/ListNode.java b/src/main/java/com/thealgorithms/datastructures/lists/ListNode.java
new file mode 100644
index 000000000000..ec015edf8be4
--- /dev/null
+++ b/src/main/java/com/thealgorithms/datastructures/lists/ListNode.java
@@ -0,0 +1,11 @@
+package com.thealgorithms.datastructures.lists;
+
+public class ListNode {
+    int value;
+    ListNode next;
+
+    public ListNode(int value) {
+        this.value = value;
+        this.next = null;
+    }
+}
diff --git a/src/test/java/com/thealgorithms/datastructures/lists/FindMiddleNodeTest.java b/src/test/java/com/thealgorithms/datastructures/lists/FindMiddleNodeTest.java
new file mode 100644
index 000000000000..18f0bb2b2eef
--- /dev/null
+++ b/src/test/java/com/thealgorithms/datastructures/lists/FindMiddleNodeTest.java
@@ -0,0 +1,30 @@
+package com.thealgorithms.datastructures.lists;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class FindMiddleNodeTest {
+
+    @Test
+    public void testOddLengthList() {
+        ListNode head = createList(new int[]{1, 2, 3, 4, 5});
+        assertEquals(3, FindMiddleNode.findMiddle(head).value);
+    }
+
+    @Test
+    public void testEvenLengthList() {
+        ListNode head = createList(new int[]{1, 2, 3, 4, 5, 6});
+        assertEquals(4, FindMiddleNode.findMiddle(head).value);
+    }
+
+    private ListNode createList(int[] values) {
+        ListNode head = new ListNode(values[0]);
+        ListNode current = head;
+        for (int i = 1; i < values.length; i++) {
+            current.next = new ListNode(values[i]);
+            current = current.next;
+        }
+        return head;
+    }
+}
+

From c58d92536a0e128db41dd73681331c7fa1194cd4 Mon Sep 17 00:00:00 2001
From: Medha Sunkad <medhasunkad13@gmail.com>
Date: Sun, 19 Oct 2025 19:56:24 +0530
Subject: [PATCH 2/2] Add FindMiddleNode algorithm with ListNode class and
 JUnit tests

---
 .../thealgorithms/datastructures/lists/FindMiddleNode.java | 7 +++++--
 .../datastructures/lists/FindMiddleNodeTest.java           | 5 ++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/main/java/com/thealgorithms/datastructures/lists/FindMiddleNode.java b/src/main/java/com/thealgorithms/datastructures/lists/FindMiddleNode.java
index 00e403c23c47..570a8d5d62e9 100644
--- a/src/main/java/com/thealgorithms/datastructures/lists/FindMiddleNode.java
+++ b/src/main/java/com/thealgorithms/datastructures/lists/FindMiddleNode.java
@@ -1,6 +1,10 @@
 package com.thealgorithms.datastructures.lists;
 
-public class FindMiddleNode {
+public final class FindMiddleNode {
+
+    private FindMiddleNode() {
+        throw new UnsupportedOperationException("Utility class");
+    }
 
     public static ListNode findMiddle(ListNode head) {
         ListNode slow = head;
@@ -24,4 +28,3 @@ public static void main(String[] args) {
         System.out.println("Middle node value: " + middle.value);
     }
 }
-// package com.thealgorithms.datastructures.lists;
\ No newline at end of file
diff --git a/src/test/java/com/thealgorithms/datastructures/lists/FindMiddleNodeTest.java b/src/test/java/com/thealgorithms/datastructures/lists/FindMiddleNodeTest.java
index 18f0bb2b2eef..e9cc152775d8 100644
--- a/src/test/java/com/thealgorithms/datastructures/lists/FindMiddleNodeTest.java
+++ b/src/test/java/com/thealgorithms/datastructures/lists/FindMiddleNodeTest.java
@@ -7,13 +7,13 @@ public class FindMiddleNodeTest {
 
     @Test
     public void testOddLengthList() {
-        ListNode head = createList(new int[]{1, 2, 3, 4, 5});
+        ListNode head = createList(new int[] { 1, 2, 3, 4, 5 });
         assertEquals(3, FindMiddleNode.findMiddle(head).value);
     }
 
     @Test
     public void testEvenLengthList() {
-        ListNode head = createList(new int[]{1, 2, 3, 4, 5, 6});
+        ListNode head = createList(new int[] { 1, 2, 3, 4, 5, 6 });
         assertEquals(4, FindMiddleNode.findMiddle(head).value);
     }
 
@@ -27,4 +27,3 @@ private ListNode createList(int[] values) {
         return head;
     }
 }
-