How to insert an item at a given position in a linked list?

Question

This how you would add an item:

public void insert (Object item)
{
    Link add = new Link();
    add.data = item;
    add.next = head;
    _head = add;
    ++_l         


        

Answer 1

You need a temporary variable that start from the head, traverse each node until the desired position or the end of the list, then insert the new node.

Since it is a homework exercise, I will only post pseudo code:

if pos < 0
    //define what to do here...
    return
end if
if pos == 0 
    //inserting at the beginning
    insert(item)
    return
end if
Link temp <- head
int index <- 0
while index < pos and temp->next != null
    temp <- temp->next
    index <- index + 1
end while
//now you're at your desired location or at the end of the list
Link newLink <- new Link
newLink->data <- item
newLink->next <- temp->next
temp->next <- newLink