Question

Implement the getNodeAtPosition function of the LinkedList class .

Node * LinkedList::getNodeAtPosition(int position)

The job of this function is to return a pointer to the node the node at the given position. If the list is empty, position <= 0 or position > length, then the function should return the null pointer.

This is a helper function that can be used by various other member functions (e.g. insertAtPosition, removeAtPosition, getValue. setValue).

I started with this:

LinkedList::LinkedList(int myArray[], int size) {
   if (position <= 0 || position > length)
   return false;
}​

Answer 1

// ConsoleApplication10.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

struct Node
{
   int info;
   struct Node *next;
}*start;

class LinkedList
{

   int main()
   {
       return 0;
   }

   Node * LinkedList::getNodeAtPosition(int position)
   {
       int pos, counter = 0;

       struct Node *temp, *s, *ptr;

       pos = position;
       int i;
       s = start;// start points to start of liked list
       while (s != NULL)
       {
           s = s->next;
           counter++;
       }
       if (pos == 1)
       {
           if (start == NULL)
           {
               return NULL;
           }
           else
           {
               ptr = start;
               return ptr;
           }
       }
       else if (pos > 1 && pos <= counter)
       {
           s = start;
           for (i = 1; i < pos; i++)
           {
               ptr = s;
               s = s->next;
           }
           ptr->next = temp;
           return temp;
       }
       else
       {
           return NULL;
       }
   }
};