/* This software was developed by Bruce Hendrickson and Robert Leland   *
 * at Sandia National Laboratories under US Department of Energy        *
 * contract DE-AC04-76DP00789 and is copyrighted by Sandia Corporation. */

#include	<stdio.h>
#include	"structs.h"
#include	"defs.h"


/* Note: bi-directional lists aren't assumed to be sorted. */

void      add2bilist(lptr, list)/* add val to unsorted list */
struct bilist *lptr;		/* element to add */
struct bilist **list;		/* list added to */
{
    lptr->next = *list;
    if (*list != NULL)
	(*list)->prev = lptr;
    lptr->prev = NULL;
    *list = lptr;
}


void      removebilist(lptr, list)
struct bilist *lptr;		/* ptr to element to remove */
struct bilist **list;		/* head of list to remove it from */

/* Remove an element from a bidirectional list. */
{
    if (lptr->next != NULL)
	lptr->next->prev = lptr->prev;
    if (lptr->prev != NULL)
	lptr->prev->next = lptr->next;
    else
	*list = lptr->next;
}


void      movebilist(lptr, oldlist, newlist)
struct bilist *lptr;		/* ptr to element to move */
struct bilist **oldlist;	/* head of list to remove it from */
struct bilist **newlist;	/* head of list to add it to */

/* Move an element from a old bidirectional list to new one. */
{
    removebilist(lptr, oldlist);

    add2bilist(lptr, newlist);
}