How to find 3rd element from end in a linked list in one pass?

Question

How to find the median of simple linked list and add a node after it? C program would be helpful?

Answer 1

/* Function to get the nth node from the last of a linked list*/
void printNthFromLast(struct node* head, int n)
{
    int len = 0, i;
    struct node *temp = head;

    // 1) count the number of nodes in Linked List
    while (temp != NULL)
    {
        temp = temp->next;
        len++;
    }

    // check if value of n is not more than length of the linked list
    if (len < n)
      return;

    temp = head;

    // 2) get the (n-len+1)th node from the begining
    for (i = 1; i < len-n+1; i++)
       temp = temp->next;

    printf ("%d", temp->data);

    return;
}