Merge pull request #1130 from akshaymagar2003/main

Middle of Linked List in java

Author: akgmage

Linked List/FindMiddleLinkedList.java

@@ -0,0 +1,48 @@
+/* 
+In this code, the ListNode class represents a node in the linked list, with an integer value val and a reference to the next node next. The FindMiddleLinkedList class has a findMiddle method that takes a ListNode as its input and returns the middle node of the linked list using the fast and slow pointers algorithm.
+
+*/
+class ListNode {
+    int val;
+    ListNode next;
+
+    ListNode(int val) {
+        this.val = val;
+        this.next = null;
+    }
+}
+
+class FindMiddleLinkedList {
+    public ListNode findMiddle(ListNode head) {
+        // Create two pointers, slow and fast, both initially pointing to the head of the linked list.
+        ListNode slow = head;
+        ListNode fast = head;
+
+        // Move the slow pointer one step at a time and the fast pointer two steps at a time, until the fast pointer reaches the end of the list.
+        while (fast != null && fast.next != null) {
+            slow = slow.next;
+            fast = fast.next.next;
+        }
+
+        // When the fast pointer reaches the end of the list, the slow pointer will be pointing to the middle of the list.
+        return slow;
+    }
+
+    public static void main(String[] args) {
+        // Create a sample linked list
+        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);
+
+        // Create an instance of the FindMiddleLinkedList class
+        FindMiddleLinkedList f = new FindMiddleLinkedList();
+
+        // Call the findMiddle method to get the middle node of the linked list
+        ListNode middleNode = f.findMiddle(head);
+
+        // Print the value of the middle node
+        System.out.println("The middle node has value: " + middleNode.val);
+    }
+}