Insert a node at a specific position in a linked list| Linked List
Task(easy)
Given the pointer to the head node of a linked list and an integer to insert at a certain position, create a new node with the given integer as its data attribute, insert this node at the desired position and return the head node. A position of 0 indicates head, a position of 1 indicates one node away from the head and so on. The head pointer given may be null meaning that the initial list is empty.
Example
head refers to the first node in the list 1->2->3
Data=4
Position=2
Insert a node at position 2 with data=4. The new list is 1->2->4->3
Function Description Complete the function insertNodeAtPosition in the editor below. It must return a reference to the head node of your finished list.
insertNodeAtPosition has the following parameters:
- head: a SinglyLinkedListNode pointer to the head of the list
- data: an integer value to insert as data in your new node
- position: an integer position to insert the new node, zero based indexing
Returns
- SinglyLinkedListNode pointer: a reference to the head of the revised list
Input Format
The first line contains an integer n, the number of elements in the linked list.
Each of the next n lines contains an integer SinglyLinkedListNode[i].data.
The next line contains an integer data, the data of the node that is to be inserted.
The last line contains an integer position.
Constraints
1<n<1000
1< SinglyLinkedListNode[i].data<1000, where SinglyLinkedListNode[i] is the element of the linked list.
0<position<n
Sample Input
3
16
13
7
1
2
Sample Output
16 13 1 7
Solution 1
def insertNodeAtPosition(llist, data, position):
node = llist
for _ in range(position - 1):
node = node.next
_next = node.next
new = SinglyLinkedListNode(data)
node.next, new.next = new, _next
return llist
Solution 2
def insertNodeAtPosition(llist, data, position):
size_list = 0
node = SinglyLinkedListNode(data)
head = llist
while llist.next:
size_list+=1
if size_list == position:
node.next = llist.next
llist.next = node
return head
else:
llist = llist.next
return head
Explanation Steps
1.Create a new node with the desired data.
2.Check if the position is 0 (insert at the head) or traverse to the node just before the desired position.
3.Update pointers to insert the new node in the correct position.
