skip k elements and reverse #500

Author: joharbatta

linkedList/classroomProblem.java

@@ -0,0 +1,82 @@
+import java.util.*;
+//reverse after k linked list
+class classroomProblem {
+    Node head;
+
+    class Node {
+        int data;
+        Node next;
+
+        Node(int d) {
+            data = d;
+            next = null;
+        }
+    }
+
+    Node reverse(Node temp) {
+
+        Node prev = null;
+        Node next = null;
+        Node curr=temp;
+
+         while (curr != null) 
+         {
+            next = curr.next;
+            curr.next = prev;
+            prev = curr;
+            curr = next;
+        }
+        return prev;
+    }
+
+    public void reverseAfter(int k) {
+
+        Node temp = head;
+        if (head == null) {
+            System.out.println("no arrangement feasible");
+        } else 
+        {
+             int count = 0;
+            while (count != k - 1) 
+            {
+                temp = temp.next;
+                count++;
+            }
+            temp.next = reverse(temp.next);
+        }
+    }
+
+      public void push(int new_data) {
+        Node temp = head;
+        Node new_node = new Node(new_data);
+        if (head == null) {
+            head = new_node;
+        } else {
+            while (temp.next != null) {
+                temp = temp.next;
+            }
+            temp.next = new_node;
+        }
+    }
+
+      public void printList() {
+        Node tnode = head;
+        while (tnode != null) {
+            System.out.print(tnode.data + " ");
+            tnode = tnode.next;
+        }
+    }
+
+    public static void main(String[] args) {
+        Scanner in = new Scanner(System.in);
+        classroomProblem obj = new classroomProblem();
+        int no = in.nextInt();
+        for (int i = 0; i < no; i++) {
+            int element = in.nextInt();
+            obj.push(element);
+        }
+        int pos = in.nextInt();
+        obj.reverseAfter(pos);
+        obj.printList();
+    }
+}