/************************************************************************/
/* File Name : lc4_memory.c		 										*/
/* Purpose   : This file implements the linked_list helper functions	*/
/* 			   to manage the LC4 memory									*/
/*             															*/
/* Author(s) : tjf and you												*/
/************************************************************************/

#include <stdio.h>
#include "lc4_memory.h"


/*
 * adds a new node to a linked list pointed to by head
 */
int add_to_list (row_of_memory** head,
		 short unsigned int address,
		 short unsigned int contents)
{

    /* check to see if there is already an entry for this address and update the contents.  no additional steps required in this case */
    
    /* allocate memory for a single node */

	/* populate fields in newly allocated node w/ address&contents, NULL for label and assembly */
	/* do not malloc() storage for label and assembly here - do it in parse_file() and reverse_assemble() */

	/* if *head is NULL, node created is the new head of the list! */

	/* otherwise, insert node into the list in address ascending order */

	/* return 0 for success, -1 if malloc fails */

	return 0 ;
}



/*
 * search linked list by address field, returns node if found
 */
row_of_memory* search_address (row_of_memory* head,
			       short unsigned int address )
{
	/* traverse linked list, searching each node for "address"  */

	/* return pointer to node in the list if item is found */

	/* return NULL if list is empty or if "address" isn't found */

	return NULL ;
}

/*
 * search linked list by opcode field, returns node if found
 */
row_of_memory* search_opcode  (row_of_memory* head,
				      short unsigned int opcode  )
{
    /* opcode parameter is in the least significant 4 bits of the short int and ranges from 0-15 */
		/* see assignment instructions for a detailed description */
    
    /* traverse linked list until node is found with matching opcode in the most significant 4 bits
	   AND "assembly" field of node is NULL */

	/* return pointer to node in the list if item is found */

	/* return NULL if list is empty or if no matching nodes */

	return NULL ;
}


void print_list (row_of_memory* head )
{
	/* make sure head isn't NULL */

	/* print out a header */
    
	/* traverse linked list, print contents of each node */

	return ;
}

/*
 * delete entire linked list
 */
int delete_list    (row_of_memory** head )
{
	/* delete entire list node by node */
	/* set the list head pointer to NULL upon deletion */

	return 0 ;
}