Reverse a linked list

                            Solution in C :

In C:

//the following function is all that is needed to complete the
//challenge in hackerrank platform.

SinglyLinkedListNode* reverse(SinglyLinkedListNode* head) {
    struct SinglyLinkedListNode* new_head = NULL;
    struct SinglyLinkedListNode* temp;
    
    while(head != NULL){
        temp = head->next;
        head->next = new_head;
        new_head = head;
        head = temp;
    }
    
    return new_head;

}









In C++:

//the following function is all that is needed to complete the
//challenge in hackerrank platform.


Node* Reverse(Node *head)
{
  // Complete this method
    Node* prev   = NULL;
    Node* current = head;
    Node* next;
    
    while (current != NULL)
    {
        next  = current->next;  
        current->next = prev;   
        prev = current;
        current = next;
    }
    
    return prev;
}










In Java:

//the following method is all that is needed to complete the
//challenge in hackerrank platform.

  static SinglyLinkedListNode reverse(SinglyLinkedListNode head) {
        SinglyLinkedListNode next = null;
        SinglyLinkedListNode current = head;
        SinglyLinkedListNode previous = null;
        while(current!=null)
        {
            next = current.next;
            current.next = previous;
            previous = current;
            current = next;
        }
        SinglyLinkedListNode singlyLinkedListNode = previous;
        return singlyLinkedListNode;
    }








In Python 3:

//the following method is all that is needed to complete the
//challenge in hackerrank platform.

def Reverse(head):
    current = head
    prev = None
    next = None
    while current is not None:
        next = current.next
        current.next = prev;  
        prev = current;
        current = next;
    
    return prev