# Linked List | Set 3 (Deleting a node)

• Difficulty Level : Easy
• Last Updated : 23 Jun, 2022

We have discussed Linked List Introduction and Linked List Insertion in previous posts on a singly linked list.
Let us formulate the problem statement to understand the deletion process. Given a ‘key’, delete the first occurrence of this key in the linked list

### Delete from a Linked List:-

You can delete an element from a list from:

1. Beginning
2. End
3. Middle

#### 1. Delete from Beginning:

Point head to the next node i.e. second node

#### 2. Delete from end:

Point head to the previous element i.e. last second element
Change next pointer to null
while(temp->next->next!=NULL)
{
temp = temp->next
}
temp->next = NULL

#### 3.Delete from Middle:

Traverse to element before the element to be deleted
Change next pointer to exclude the node from the chain
for(int i=2; i< position; i++)
{
if(temp->next!=NULL)
{
temp = temp->next;
}
}

temp->next = temp->next->next;

Iterative Method:
To delete a node from the linked list, we need to do the following steps.
1) Find the previous node of the node to be deleted.
2) Change the next of the previous node.
3) Free memory for the node to be deleted.

Since every node of the linked list is dynamically allocated using malloc() in C, we need to call free() for freeing memory allocated for the node to be deleted.

## Javascript



Output

2  3  1  7
Linked List after Deletion of 1:
2  3  7

Time Complexity: O(n)

Auxiliary Space: O(1)

Recursive Method:

To delete a node of a linked list recursively we need to do the following steps.

1. We pass node* (node pointer) as a reference to the function (as in node* &head)

2. Now since the current node pointer is derived from the previous node’s next (which is passed by reference) so now if the value of the current node pointer is changed, the previous next node’s value also gets changed which is the required operation while deleting a node (i.e points previous node’s next to current node’s (containing key) next).

3. Find the node containing the given value.

4. Store this node to deallocate it later using the free() function.

5. Change this node pointer so that it points to its next and by performing this previous node’s next also gets properly linked.

Below is the implementation of the above approach.

## C++

Element not present in the list
15 14 12 10
15 14 12
15 12

Time Complexity: O(n)

Auxiliary Space: O(n) (due to recursion call stack)