PLEASE DO NOT USE BUILT IN FILES OR FUNCTIONS! Write a program in c++ and make sure it works, that reads a list of students (first names only) from a file. It is possible for the names to be in unsorted order in the file but they have to be placed in sorted order within the linked list. The program should use a doubly linked list. Each node in the doubly linked list should have the student’s name, a pointer to the next student, and a pointer to the previous student. Here is a sample visual. The head points to the beginning of the list. The tail points to the end of the list. When inserting consider all the following conditions: if(!head){ //no other nodes }else if (strcmp(data, head->name)<0){ //smaller than head }else if (strcmp(data, tail->name)>0){ //larger than tail }else{ //somewhere in the middle }

1. Do you have any suggestions about how I should start this lab?

A: Make sure that you draw out the nodes on a piece of paper so that you know exactly what is being connected to what. If you try to do this in your head, then more than likely, you will not do well.

1. What do I do with duplicate names?

A: Ignore it.

1. Do I need to use some sort of sort function to sort the nodes?

A: No, do not use any of the usual sorting algorithms. It will complicate life. Once you create a node, you need to decide where it goes in the doubly linked list. It can go in the beginning which affects the head. It can go at the end which affects the tail. It can go in the middle which means it doesn’t affect either

Once you create your node, start traversing through your linked list. A variable like curr will point to the node in your linked list that you are on. Compare the name in curr with the name in the newly created node. If the name in curr node is bigger, then you have found the spot to insert your node. If the name in curr node is smaller, then you continue to move to the next node in your list. If you have reached the end of the list and the name in curr node is smaller, then you have to insert at the end and update the tail. If the name in the curr node is bigger and you are at the beginning of your list, then you have a new head. If the names are the same, then you can just get out because you have a duplicate

if(!head){ //no other nodes

}else if (strcmp(data, head->name)<0){ //smaller than head

}else if (strcmp(data, tail->name)>0){ //larger than tail

}else{ //somewhere in the middle

Use a loop to traverse through the list to find the location of where you need to insert

}

1. Can I use any of the built-in library for linked lists?

A: No, you create everything from scratch

1. Can I read the items from the file into some other data structure, sort it and then recreate my linked list

A: No, you sort as you insert into your linked list.

1. Can you provide a general pseudocode to get me started?

//you will not be reading the entire line but rather one word at a time

Loop through the file as long as there is something to read

Read word//reads first word which could be the word delete or a name

If the string==’delete’

Read word //this means that the next word is a name

Delete (word) //look for the node and delete it

Else

//the line just contained a name which means you insert

Insert (word)

Traverse() //Traverse through the list, display in ascending, descending order

Doubly contains head and tail as instance variables, delete,insert, traverseAsending, traverseDescnding methods. Since all variables are private, provide getter and setter methods

Node will contain value, prev, next as instance variables, Since all the variables will be private, provide getter and setter methods.

Driver will contain the main method which will contain the content from item 6 in this document