Glib学习（2） 双向链表 Doubly-Linked Lists

首先贴出来glib库的帮助文档网址

http://web.mit.edu/barnowl/share/gtk-doc/html/glib/glib-Doubly-Linked-Lists.html#g-list-find

由于双向链表与单向链表的很多函数功能和名称都是一样的，这里对一些函数就不细说了，具体有什么不了解的可以通过上面给的网址了解。

函数先说一下双向链表的结构体

GList

typedef struct {
  gpointer data;
  GList *next;
  GList *prev;
} GList;

Doubly-Linked Lists — linked lists containing integer values or pointers to data, with the ability to iterate over the list in both directions。

这个是双向链表的官方描述，其中说的的数据可以是int型的值或者是指针类型，我觉得就是32为能够表示的就可以了，你愿意的话char型的也可以存储，就是浪费空间而已。

然后是他所支持的功能函数

Synopsis

#include <glib.h>


                    GList;

GList*              g_list_append                       (GList *list,
                                                         gpointer data);
GList*              g_list_prepend                      (GList *list,
                                                         gpointer data);
GList*              g_list_insert                       (GList *list,
                                                         gpointer data,
                                                         gint position);
GList*              g_list_insert_before                (GList *list,
                                                         GList *sibling,
                                                         gpointer data);
GList*              g_list_insert_sorted                (GList *list,
                                                         gpointer data,
                                                         GCompareFunc func);
GList*              g_list_remove                       (GList *list,
                                                         gconstpointer data);
GList*              g_list_remove_link                  (GList *list,
                                                         GList *llink);
GList*              g_list_delete_link                  (GList *list,
                                                         GList *link_);
GList*              g_list_remove_all                   (GList *list,
                                                         gconstpointer data);
void                g_list_free                         (GList *list);

GList*              g_list_alloc                        (void);
void                g_list_free_1                       (GList *list);
#define             g_list_free1

guint               g_list_length                       (GList *list);
GList*              g_list_copy                         (GList *list);
GList*              g_list_reverse                      (GList *list);
GList*              g_list_sort                         (GList *list,
                                                         GCompareFunc compare_func);
gint                (*GCompareFunc)                     (gconstpointer a,
                                                         gconstpointer b);
GList*              g_list_insert_sorted_with_data      (GList *list,
                                                         gpointer data,
                                                         GCompareDataFunc func,
                                                         gpointer user_data);
GList*              g_list_sort_with_data               (GList *list,
                                                         GCompareDataFunc compare_func,
                                                         gpointer user_data);
gint                (*GCompareDataFunc)                 (gconstpointer a,
                                                         gconstpointer b,
                                                         gpointer user_data);
GList*              g_list_concat                       (GList *list1,
                                                         GList *list2);
void                g_list_foreach                      (GList *list,
                                                         GFunc func,
                                                         gpointer user_data);
void                (*GFunc)                            (gpointer data,
                                                         gpointer user_data);

GList*              g_list_first                        (GList *list);
GList*              g_list_last                         (GList *list);
#define             g_list_previous                     (list)
#define             g_list_next                         (list)
GList*              g_list_nth                          (GList *list,
                                                         guint n);
gpointer            g_list_nth_data                     (GList *list,
                                                         guint n);
GList*              g_list_nth_prev                     (GList *list,
                                                         guint n);

GList*              g_list_find                         (GList *list,
                                                         gconstpointer data);
GList*              g_list_find_custom                  (GList *list,
                                                         gconstpointer data,
                                                         GCompareFunc func);
gint                g_list_position                     (GList *list,
                                                         GList *llink);
gint                g_list_index                        (GList *list,
                                                         gconstpointer data);

void                g_list_push_allocator               (gpointer allocator);
void                g_list_pop_allocator                (void);

下面贴出例子程序，这里就不分开单独讲解，因为很多和单链表相似的地方

#include <stdio.h>
#include <stdlib.h>
#include <glib.h>
//#include <glib/gprintf.h>

static gint
sort(gconstpointer p1, gconstpointer p2)//排序函数，正向排序
{
    gint32 a, b;
    
    a = GPOINTER_TO_INT(p1);
    b = GPOINTER_TO_INT(p2);

    return (a > b ? +1 : a == b ? 0 : -1);
}

static gint
sort_r(gconstpointer p1, gconstpointer p2)//逆向排序
{
    gint32 a, b;
    
    a = GPOINTER_TO_INT(p1);
    b = GPOINTER_TO_INT(p2);

    return (a < b ? +1 : a == b ? 0 : -1);
}

static void
print(gpointer p1, gpointer p2)//打印函数，只打印P1
{
    g_printf("%d,", *(gint*)p1);
}

static void
test_list(void)
{
    GList *list = NULL;
    gint nums[10] = {0,1,2,3,4,5,6,7,8,9};

// GList* g_list_append(GList *list, gpointer data);//尾加，和单链表是一样的功能
    list = g_list_append(list, &nums[1]);
    g_printf("The first item should be '%d' now.\t\tResult: %d.\n", nums[1], *(gint*)list->data);
// GList* g_list_prepend(GList *list, gpointer data);//头加
    list = g_list_prepend(list, &nums[0]);
// GList* g_list_first(GList *list);//获得头指针
    g_printf("The first item should be '%d' now.\t\tResult: %d.\n", nums[0], *(gint*)g_list_first(list)->data);
// GList* g_list_insert(GList *list, gpointer data, gint position);//在position位置插入data数据
    list = g_list_insert(list, &nums[2], 2);
// GList* g_list_last(GList *list);         返回链表最后一个的指针
    g_printf("The last item should be '%d' now.\t\tResult: %d.\n", nums[2], *(gint*)g_list_last(list)->data);
// GList* g_list_insert_before(GList *list, GList *sibling, gpointer data);     在链表指针sibling处前面插入data数据，NULL是最后一个的指针
    list = g_list_insert_before(list, NULL, &nums[3]);
    g_printf("The last item should be '%d' now.\t\tResult: %d.\n", nums[3], *(gint*)g_list_last(list)->data);
// #define g_list_next (list)           在list指针处的下一个指针，这个和单链表的next是一样的
    g_printf("The second item should be '%d' now.\t\tResult: %d.\n", nums[1], *(gint*)g_list_next(list)->data);
// #define g_list_previous (list)       这个是list指针处的前一个指针，这个是单链表无法容易做到的，双向链表中的双向优势
    g_printf("The first item should be '%d' now.\t\tResult: %d.\n", nums[0], *(gint*)g_list_previous(g_list_next(list))->data);
// gint g_list_index(GList *list, gconstpointer data);  查找data首次出现的位置
    g_printf("The index of '%d' should be '%d' now.\t\tResult: %d.\n", nums[2], 2, g_list_index(list, &nums[2]));
// gint g_list_position(GList *list, GList *llink);     返回link在list链表中的位置
    g_printf("The position of the third item should be 2 now.\t\tResult: %d.\n", g_list_position(list, g_list_next(list)->next));
// guint g_list_length(GList *list);        链表长度
    g_printf("The length of list should be 4 now.\t\tResult: %d.\n", g_list_length(list));
    
    GList *lt = NULL;
    gint i;
    
// GList* g_list_insert_sorted(GList *list, gpointer data, GCompareFunc func);      按照func的规则排序插入
    for (i = 4; i < 10; i++)
        lt = g_list_insert_sorted(lt, &nums[i], sort_r);//逆向排序插入，9,8,7,6,5,4
// GList* g_list_reverse(GList *list);      翻转链表，翻转后是正序了，4,5,6,7，8,9
    lt = g_list_reverse(lt);
    
    g_printf("The second half of list should be sored now.\nResult:");
// gpointer g_list_nth_data(GList *list, guint n);      返回在位置n的数据
    for (i = 4; i < 10; i++)
        g_printf("%d,",*(gint*)(g_list_nth_data(lt, i-4)));
    g_printf("\n");

// GList* g_list_concat(GList *list1, GList *list2);       拼接list1和list2，这里的list2的内容并不是复制的，而是直接连接的
    list = g_list_concat(list, lt);
    g_printf("The list should have all items which should be sored now.\nResult:");
// void g_list_foreach(GList *list, GFunc func, gpointer user_data);    调用func函数去操作list的每个元素，前面print函数是打印了list中的元素，user_data是func的第二个参数
    g_list_foreach(list, print, NULL);
    g_printf("\n");

// GList* g_list_sort(GList *list, GCompareFunc compare_func);      将链表中的元素按照func的规则进行排序
    list = g_list_sort(list, sort_r);//逆向排序
    g_printf("The list should have all items which should be sored reversed now.\nResult:");
    g_list_foreach(list, print, NULL);
    g_printf("\n");

    GList *lb = NULL;
// GList* g_list_copy(GList *list);     复制链表，仅仅是指针的复制，并没有进行数据的复制
    lb = g_list_copy(list);
    g_printf("The backup list should have the same item and sequence now.\nResult:");
// GList* g_list_nth(GList *list, guint n);     返回位置n的链表指针
    for (i = 0; i < 10; i++) {
        GList *ltmp = g_list_nth(lb, i);
        g_printf("%d,", *(gint*)ltmp->data);
    }
    g_printf("\n");

// GList* g_list_sort_with_data(GList *list, GCompareDataFunc compare_func, gpointer user_data);    和g_list_sort()函数一样，只是能够接受一个用户参数user_data
    lb = g_list_sort_with_data(lb, (GCompareDataFunc)sort, NULL);
    g_printf("The backup list should have all items which should be sored now.\nResult:");
    g_list_foreach(lb, print, NULL);
    g_printf("\n");

    GList *lall = NULL;
    lall = g_list_concat(list, lb);
    g_printf("The concated list should have all items now.\nResult:");
    g_list_foreach(lall, print, NULL);
    g_printf("\n");

// GList* g_list_remove(GList *list, gconstpointer data);   删除数据data，只删除第一个出现的元素
    lall = g_list_remove(lall, &nums[0]);
    g_printf("The list should have only one '%d' item now.\nResult:", nums[0]);
    g_list_foreach(lall, print, NULL);
    g_printf("\n");

// GList* g_list_remove_all(GList *list, gconstpointer data);   删除data，不仅仅是第一个，所有的都删除
    lall = g_list_remove_all(lall, &nums[9]);
    g_printf("The list should not have '%d' item now.\nResult:", nums[9]);
    g_list_foreach(lall, print, NULL);
    g_printf("\n");
    
    GList *ll = NULL;
// GList* g_list_find(GList *list, gconstpointer data);         找到数据data在链表中的位置，返回元素指针
    g_printf("The list should find '%d' now.\t\tResutl: %d.\n", nums[0], (ll = g_list_find(lall, &nums[0])) ? *(gint*)ll->data : -1);
// GList* g_list_find_custom(GList *list, gconstpointer data, GCompareFunc func);       根据func条件查找data，如果没找到返回null
    g_printf("The list should not find '%d' now.\t\tResutl: %d.\n", nums[9], (ll = g_list_find_custom(lall, &nums[9], sort)) ? *(gint*)ll->data : -1);

// void g_list_free(GList *list);
    g_list_free(lall);
}

int
main(void)
{
    printf("BEGIN:\n************************************************************\n");
    test_list();
    printf("\n************************************************************\nDONE\n");
    return 0;
}

下面是运行结果：

linux@ubuntu:~/16021/glibdemo$ ls
Doubly_Linked_Lists.c  glist  hello  helloworld.c  slist  slist.c
linux@ubuntu:~/16021/glibdemo$ gcc -o Doubly_Linked_Lists Doubly_Linked_Lists.c -lglib-2.0
linux@ubuntu:~/16021/glibdemo$ ls
Doubly_Linked_Lists  Doubly_Linked_Lists.c  glist  hello  helloworld.c  slist  slist.c
linux@ubuntu:~/16021/glibdemo$ ./Doubly_Linked_Lists 
BEGIN:
************************************************************
The first item should be '1' now.               Result: 1.
The first item should be '0' now.               Result: 0.
The last item should be '2' now.                Result: 2.
The last item should be '3' now.                Result: 3.
The second item should be '1' now.              Result: 1.
The first item should be '0' now.               Result: 0.
The index of '2' should be '2' now.             Result: 2.
The position of the third item should be 2 now.         Result: 2.
The length of list should be 4 now.             Result: 4.
The second half of list should be sored now.
Result:4,5,6,7,8,9,
The list should have all items which should be sored now.
Result:0,1,2,3,4,5,6,7,8,9,
The list should have all items which should be sored reversed now.
Result:9,8,7,6,5,4,3,2,1,0,
The backup list should have the same item and sequence now.
Result:9,8,7,6,5,4,3,2,1,0,
The backup list should have all items which should be sored now.
Result:0,1,2,3,4,5,6,7,8,9,
The concated list should have all items now.
Result:9,8,7,6,5,4,3,2,1,0,0,1,2,3,4,5,6,7,8,9,
The list should have only one '0' item now.
Result:9,8,7,6,5,4,3,2,1,0,1,2,3,4,5,6,7,8,9,
The list should not have '9' item now.
Result:8,7,6,5,4,3,2,1,0,1,2,3,4,5,6,7,8,
The list should find '0' now.           Resutl: 0.
The list should not find '9' now.               Resutl: -1.


************************************************************
DONE
linux@ubuntu:~/16021/glibdemo$