双链表

直接看实现吧：

#include <cstdio>
#include <cstdlib>

typedef int itemType;
struct Node;
typedef struct Node *pNode;
typedef pNode list;
typedef pNode position;

struct Node {
    itemType item;
    position prev, next;
};

list
MakeEmpty(list l)
{
    l->item = 0;
    l->prev = NULL;
    l->next = NULL;
}

int
IsEmpty(list l)
{
    /*
    if (l->next == NULL) {
        return 1;
    } else {
        return 0;
    }
    */
    return l->next == NULL;
}

int
IsLast(position p, list l)
{
    return p->next == NULL;
}

position
Find(itemType item, list l)
{
    position p;
    
    p = l->next;
    while (p != NULL && p->item != item) {
        p = p->next;
    }
    
    return p;
}
/*
position
FindPrevious(itemType item, list l)
{
    position p;
    
    p = l;
    while (p->next != NULL && p->next->item != item) {
        p = p->next;
    }
    
    return p;
}
*/
void
Delete(itemType item, list l)
{
    position p, tmp;
    
    p = Find(item, l);
    
    if (p != NULL) {
        if (p->next == NULL) {
            p->prev->next = NULL;
        } else {
            p->next->prev = p->prev;
            p->prev->next = p->next;
        }
        free(p);
    }
}

void
Insert(itemType item, list l, position p)
{
    position tmp;
    
    tmp = (position)malloc(sizeof(struct Node));
    if (tmp == NULL) {
        printf("Out of space!\n");
        return;
    }
    
    tmp->item = item;
    tmp->next = p->next;
    tmp->prev = p;
    p->next = tmp;
}

void
DeleteList(list l)
{
    position p, tmp;
    
    p = l->next;
    while (p != NULL) {
        tmp = p;
        p = p->next;
        free(tmp);
    }   
    free(l);
}

position
Header(list l)
{
    return l;
}

position
First(list l)
{
    return l->next;
}

position
Advance( position p )
{
    return p->next;
}

itemType
Retrieve( position p )
{
    return p->item;
}

void
PrintList( list l)
{
    position p;
    p = First(l);
    while (p != NULL) {
        printf("%d\t", Retrieve(p));
        p = Advance(p);
    }
    printf("\n");
}

int
main(int argc, char** argv)
{
    list l;
    // init
    l = (list)malloc(sizeof(struct Node));
    MakeEmpty(l);
    // insert some elememts
    position p;
    p = Header(l);
    for (int i = 0; i < 10; i++) {
        Insert(i, l, p);
        p = Advance(p);
    }
    // retrieve
    PrintList(l);
    // find and delete
    Delete(0, l);
    Delete(9, l);
    Delete(100, l);
    PrintList(l);
    
    printf("%d\n", l->next->next->prev->item);
    
    system("pause");
    return 0;
}