#include <stdio.h>
#include <stdlib.h>
#include "linkedlist.h"

int main(int argc, char **argv)
{

    void * oTemp;
    //With a double pointer the word itself (ie 'pHead') can be thought of as a pointer itself
    //to get the data you just need pHead
    struct element ** pHead;
    struct element ** pTail;
    struct element * h;
    struct element * t;

    int cycle;
    int removeData;
    int loadData [20] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20};
    int loadData2 [20] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20};

    t = NULL;
    h = NULL;
    pHead = &h;
    pTail = &t;

    for( cycle = 0; cycle<20; cycle++){

        oTemp = &loadData[cycle];
        addFirst(oTemp, pHead, pTail);

        h = *pHead;
    }


    for( removeData = 0; removeData <20; removeData++){
        removeFirst(pHead, pTail);
    }

    t = NULL;
    h = NULL;
    pHead = &h;
    pTail = &t;


    for( cycle = 0; cycle<20; cycle++){
        oTemp = &loadData2[cycle];
        addLast(oTemp, pHead, pTail);
        t = *pTail;
        printf("Value in pTail: %d\n",  *(int *)t->pData);
    }


    for( removeData = 0; removeData <20; removeData++){
        removeFirst(pHead, pTail);
    }
}









#include "linkedlist.h"
#include <stdio.h>
#include <stdlib.h>

/*Functions from LinkedList.h*/

void addLast(void * oTemp, struct element ** pHead, struct element ** pTail){
	/*
	*New element is created and data is allocated. Then set as head.
	*/
	struct element * new2Last= (struct element*)malloc(sizeof(struct element));
	struct element *headLast;

	//By passing in **pHead we are passing in a POINTER to a POINTER
	//So now to manipulate this pointer we need to have access to it
	//need to test if there is data in the head
	//valgrind for testing memory leaks

	if(*pTail == NULL){
		new2Last->pData = oTemp;
		new2Last->pNext = NULL;
		*pTail = new2Last;
		*pHead = new2Last;
	}
	else{
		headLast = *pTail;
		new2Last->pData = oTemp;
		headLast->pNext = new2Last;
		new2Last->pNext = NULL;

		*pTail = new2Last;
	}


}


void addFirst(void * oTemp, struct element ** pHead, struct element ** pTail){

	/*
	*New element is created and data is allocated. Then set as head.
	*/
	struct element * new2 = (struct element*)malloc(sizeof(struct element));
	struct element *head;

	//By passing in **pHead we are passing in a POINTER to a POINTER
	//So now to manipulate this pointer we need to have access to it

	//need to test if there is data in the head
	//valgrind for testing memory leaks

	if(*pHead == NULL){
		new2->pData = oTemp;
		new2->pNext = NULL;
		*pHead = new2;
		*pTail = new2;
	}
	else{
		head = *pHead;
		new2->pData = oTemp;
		new2->pNext = head;
		*pHead = new2;
	}


}

void * removeFirst(struct element ** pHead, struct element ** pTail){

	/*We need to return a void pointer that has the data of the element we are removing
	*To do this we need to store this data in a void pointer, so we can return it
	*For correct memeory allocation we also need to free the entire element
	*So first we must save the data in the element the head is pointing to and then free the element
	*/
	void *remove;
    struct element *head;
	head = *pHead;
	remove = head->pData;
	*pHead = head -> pNext;
	free(head);
	return remove;


	//Save the element after the head
	//free the head
	//make the pointer to the head eqaul to the saved node
}
















/**************************************************************************************************************************
			DO NOT CHANGE THE CONTENTS OF THIS FILE FOR YOUR COURSEWORK. ONLY WORK WITH THE OFFICIAL VERSION
**************************************************************************************************************************/

#include <stdio.h>

struct element
{
	void * pData;
	struct element * pNext;
};

void addLast(void * oTemp, struct element ** pHead, struct element ** pTail);
void addFirst(void * oTemp, struct element ** pHead, struct element ** pTail);
void * removeFirst(struct element ** pHead, struct element ** pTail);