Single Linked List (Deleting the Last Node)

Data Structures: Deleting the Last Node of a Singly Linked List
Topics discussed:
1) C Program for deleting the last node of single linked lists.

Music:
Axol x Alex Skrindo - You [NCS Release]

#DataStructuresByNeso #DataStructures #LinkedList #SingleLinkedList

[nikhilbantu]

After creating all nodes, let's take ptr=head and while(ptr->link->link !=null) in this loop we will write ptr=ptr->link.after the loop ptr points the node before the last node we want to delete .we will free ptr->link and make ptr->link =null .

[beyinvekalp]

can't imagine computer engineering without @neso Academy. Thank you 🥰🥰🥰

[sudhanwapande]

This course is really good.. Appreciate you for providing this premium course in free

[AnimeManiaa]

Instead of using temp2, we can use temp->link->link != NULL in the while loop to delete last node using single pointer
void del(struct point* head)
{
struct point *ptr=head;
while(ptr->link->link !=NULL)
{
ptr=ptr->link;
}
free(ptr->link);
ptr->link = NULL;

}
}

[anuvindm]

Yes, we can delete the last node with only one pointer except head.

First we will traverse the list and once ptr->link is NULL we have reached the last node and we can free it by free(ptr).
_Now note that we need a variable 'count 'in the traversal which is incremented each time through the while loop (initially count=1). Now, when the traversal is over we will get a number count (here, count will be 3 as there are 3 nodes).
Next part is to traverse the list again within a loop which iterates < count times (here, < 3 times. i.e, 2 times). So we will get the 2nd node and we can assign ptr -> link = NULL

*This might not get in your head because of the way I am explaining, but this way works and this is a simple way for sure and I am just explaining my method, you guys can have your own way*

[swornimshah]

// simple step is to use link->link approach, this you we get the second last node in a linked list
while(temp->link !=NULL && temp->link->link != NULL)
temp = temp->link;
// temp = second last node

// the reason for checking temp->link != NULL is to avoid null pointer crashes i.e NULL->link crashes program

[shivp]

Solution with only one pointer:

void delete_end(struct node *head)
{
struct node *ptr = head;
if(head == NULL) printf("List is already empty");
else if(head->link == NULL) {
free(head);
head = NULL;
}
else {
while(ptr->link->link != NULL) {
ptr = ptr->link;
}
free(ptr->link);
ptr-> NULL;
}

[atulmishra]

Thank you sir for posting such a good content . And providing a free education . Your way of explaining is really very good .
Keep it up sir . 👍

[tiffinsuresh]

we do have to update head. In case if there's only one node we free the node and make head = NULL which means head will get updated in one of the conditions. So we have to return head as it gets updated.

[coders]

Yes..we can do it with single pointer except head pointer...1st we assign head->link->link=null and 3rd pointer is on 3rd elements and we'll free this 3rd pointer by assigned null to this(supposed to be 3 elements in our LL)

[ganeshreddykomitireddy]

We can do delete the last node by traversing through the list and finding the length of the list(count).And then intialize n=0
, Ptr=head and then
while(n!=count-1)
{
n++;
Ptr=Ptr->link;
}
Now Ptr is pointing to the n-1 th node.
Ptr->link=NULL;

[csworld]

I like your afford and hardworking.... Please keep continue

[maca]

I have one doubt sir, are you going to upload array topic videos in data structures or array videos in C programming playlists are enough. BTW thanks for uploading regularly sir!!😊

[Pk-swip]

I did with this method "struct node *DeleteLast_Node(struct node* head){
struct node *temp = head;

temp = temp->link;
}
free(temp->link);
temp->link = NULL;
return head;
}"

[KavyaPotnuru]

Your teaching is very good and easily undest

[Codevibe]

Thank you so much for these lectures, These are too helpful 😊

[HarshKumar-eclv]

Can u provide a python programming course also?

[usamakhan-yyee]

1. Insert a Node at the start of a linked list. (Cover all edge cases)
2. Insert a Node at the end of a linked list. (Cover all edge cases)
3. Remove a Node at the end of a linked list (Cover all edge cases)

[daverussell]

and if you working with current like the last lecture where you insert at the end using current you should update the current also to the temp2 because if you delete the last node the current will be point to unknown memory allocation

[souradipkumarsaha]

You are awesome ...waiting for.more lectures