Merge pull request #440 from prtk418/prtk418_find_middle_of_linked_list_in_java

program added

Author: t2013anurag

linked_list/middle_of_linked_list.java

@@ -0,0 +1,71 @@
+class LinkedList
+{
+    Node head; // head of linked list
+ 
+    /* Linked list node */
+    class Node
+    {
+        int data;
+        Node next;
+        Node(int d)
+        {
+            data = d;
+            next = null;
+        }
+    }
+ 
+    /* Function to print middle of linked list */
+    void printMiddle()
+    {
+        Node slow_ptr = head;
+        Node fast_ptr = head;
+        if (head != null)
+        {
+            while (fast_ptr != null && fast_ptr.next != null)
+            {
+                fast_ptr = fast_ptr.next.next;
+                slow_ptr = slow_ptr.next;
+            }
+            System.out.println("The middle element is [" +
+                                slow_ptr.data + "] \n");
+        }
+    }
+ 
+    /* Inserts a new Node at front of the list. */
+    public void push(int new_data)
+    {
+        /* 1 & 2: Allocate the Node &
+                  Put in the data*/
+        Node new_node = new Node(new_data);
+ 
+        /* 3. Make next of new Node as head */
+        new_node.next = head;
+ 
+        /* 4. Move the head to point to new Node */
+        head = new_node;
+    }
+ 
+    /* This function prints contents of linked list
+       starting from  the given node */
+    public void printList()
+    {
+        Node tnode = head;
+        while (tnode != null)
+        {
+            System.out.print(tnode.data+"->");
+            tnode = tnode.next;
+        }
+        System.out.println("NULL");
+    }
+ 
+    public static void main(String [] args)
+    {
+        LinkedList llist = new LinkedList();
+        for (int i=5; i>0; --i)
+        {
+            llist.push(i);
+            llist.printList();
+            llist.printMiddle();
+        }
+    }
+}