How to insert new node in a singly linked list after nth position?

Question

OKay, so I want to insert a new node in a singly linked list in C at the nth position(not end or beginning), but all I get after searching is that how to insert new nodes at beginning or end of a linked list. Any help is appreciated. Thanks.

it's a half-way between those solutions, but you have to count steps. — Jasen, Dec 29 '14 at 06:52

score 3 · Accepted Answer · answered Dec 29 '14 at 06:58

3

something like this perhaps.

 void insert_at(list_node **list, list_node *new,int offset)
 {
     while(offset-- && (*list)->next )
        list=&((*list)->next);
     new->next=(*list)->next
     (*list)->next=new;
 }

answered Dec 29 '14 at 06:58

Jasen

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score 1 · Answer 2 · edited Oct 24 '20 at 09:49

This will work:

void InsertNode(int position, int newdata)

{
    struct Node* temp = (struct Node* )malloc(sizeof(struct Node* ));
    temp->data=newdata;    
    struct Node* temp2=head;
    
    if(position==1)
    {
        temp->next=temp2;
        head=temp;
        return ;
    }
        
    for(int i=1;i<position;i++)
    {
        temp2=temp2->next;
    }

    temp->next=temp2->next;
    temp2->next=temp;
    return;
}

Anony Mous · Answer 3 · 2014-12-29T13:53:28.853

I have found the solution myself. This is my algorithm -

Step 1- given a linked list, index it.

Step 2- Ask for the index after which the user wants to insert the new node

Step 3- Traverse though the linked list until you have reached that index

Step 4- Make a new node which points to the node after the current index

Step 5- Make the node of the index inputted by the user point to the new node

Voila, done!

How to insert new node in a singly linked list after nth position?

3 Answers3