**Insert a Node at the head of a Linked List**

### Problem Statement :

Given a pointer to the head of a linked list, insert a new node before the head. The next value in the new node should point to head and the data value should be replaced with a given value. Return a reference to the new head of the list. The head pointer given may be null meaning that the initial list is empty. Function Description: Complete the function insertNodeAtHead in the editor below. insertNodeAtHead has the following parameter(s): 1. SinglyLinkedListNode llist: a reference to the head of a list 2. data: the value to insert in the data field of the new node Input Format: The first line contains an integer n, the number of elements to be inserted at the head of the list. The next n lines contain an integer each, the elements to be inserted, one per function call. Constraints: 1. 1<=n<=1000 2. 1<=list[i]<=1000

### Solution :

` ````
Solution in C :
In C:
//The following function is all you need to complete the
// challenge in hackerrank platform
SinglyLinkedListNode* insertNodeAtHead(SinglyLinkedListNode* llist, int data) {
SinglyLinkedListNode* new = malloc(sizeof(SinglyLinkedListNode));
new->data = data;
if(llist == NULL){
llist = new;
new->next = NULL;
return llist;
}
new-> next = llist;
llist = new;
return llist;
}
In C++:
//The following function is all you need to complete the challenge
//in hackerrank platform.
Node* Insert(Node *head,int data)
{
Node *n = new Node();
n->data = data;
n->next=head;
return head = n;
}
In Java:
//the following method is all you need to complete the challenge in
//hackerrank platform.
static SinglyLinkedListNode insertNodeAtHead(SinglyLinkedListNode head, int data) {
SinglyLinkedListNode node = new SinglyLinkedListNode(data);
if (head == null) {
return node;
} else {
node.next = head;
head = node;
return head;
}
}
In Python 3:
# the following method is all that is needed to complete the
# challenge in hackerrank platform
def Insert(head, data):
newNode = Node(data, head)
return newNode
```

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