Reversing a linked list

Reversing a linked list

Input : 1->2->3->4->5

Ouput : 5>-4->-3>-2->1

So the code goes here :

public void reverse(ListNode head){

    ListNode current = head;
    ListNode next;
    ListNode prev=null;

    while(current != null){

         next = current.next;

         next->null

         current.next = prev;

         current.next->4->3->2->1

         current->5->4->3->2->1

         prev = current;

         prev->5->4->3->2->1

         current = next;

         current->null;

   }

   head = prev;

}

Understanding the code:

Say the list is :

(head)->1->2->3->4->5

Node current = head;

current->1->2->3->4->5

Node next;

next->null;

Node prev = null;

prev->null

//in the loop

//1st iteration

next = current.next;

next->2->3->4->5

current.next = prev;

current.next->null

current->1

prev = current;

prev->1

current = next;

current->2->3->4->5

//2nd iteration

next = current.next;

next->3->4->5

current.next = prev;

current.next->1

current->2->1

prev = current;

prev->2->1

current = next;

current->3->4->5

//3rd iteration

next = current.next;

next->4->5

current.next = prev;

current.next->2->1

current->3->2->1

prev = current;

prev->3->2->1

current = next;

current->4->5

//4^th iteration

next = current.next;

next->5

current.next = prev;

current.next->3->2->1

current->4->3->2->1

prev = current;

prev->4->3->2->1

current = next;

current->5

//5^th iteration

next = current.next;

next->null

current.next = prev;

current.next->4->3->2->1

current->5->4->3->2->1

prev = current;

prev->5->4->3->2->1

current = next;

current->null;

prev points to the head of the linked list

prev->5->4->3->2->1

It's reversed.