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ReverseLinkedList
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ReverseLinkedList
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public class LinkedList
{
static LinkedListNode head;
static class LinkedListNode
{
int val;
LinkedListNode next;
LinkedListNode(int d)
{
val = d;
next = null;
}
}
public LinkedListNode reverseList(LinkedListNode head, Stack<Integer> stk)
{
if (head == null || head.next == null)
{
return head;
}
while(head != null)
{
stk.push(head.val);
head = head.next;
}
LinkedListNode head1 = null;
while(stk.empty() == false)
{
if(head == null)
{
head1 = new LinkedListNode(stk.peek());
head = head1;
stk.pop();
}
else
{
head.next = new LinkedListNode(stk.peek());
stk.pop();
head = head.next;
}
}
return head1;
}
public void printList(LinkedListNode h)
{
LinkedListNode t = h;
while (t != null)
{
System.out.print(t.val + " ");
t = t.next;
}
System.out.println();
}
// main method
public static void main(String argvs[])
{
LinkedListStack listObj = new LinkedListStack();
listObj.head = new LinkedListNode(4);
listObj.head.next = new LinkedListNode(6);
listObj.head.next.next = new LinkedListNode(7);
listObj.head.next.next.next = new LinkedListNode(1);
listObj.head.next.next.next.next = new LinkedListNode(5);
listObj.head.next.next.next.next.next = new LinkedListNode(8);
listObj.head.next.next.next.next.next.next = new LinkedListNode(3);
listObj.head.next.next.next.next.next.next.next = new LinkedListNode(2);
Stack<Integer> stk = new Stack<Integer>();
System.out.println("The Linked list before reversal is: ");
listObj.printList(head);
head = listObj.reverseList(head, stk);
System.out.println(" ");
System.out.println("After reversal, the linked list is: ");
listObj.printList(head);
}
}