Glib 函数从未排序的链表中删除重复项

我尝试编写一个函数，从

GList*列表

未排序的链接列表中删除重复项，并返回不带重复项的

GList*列表

：

GList *remove_dup (GList *list)
{
    GList *a, *b, *dup;
    a = list;

    /* Pick elements one by one */
    while (a != NULL && a->next != NULL) {
        b = a;

        /* Compare the picked element with rest of the elements */
        while (b->next != NULL) {
            /* If duplicate then delete it */
            if (a->data == b->next->data) {
                /* sequence of steps is important here */
                dup = b->next;
                b->next = b->next->next;
                g_list_free_1 (dup);
            } else  /* This is tricky */ {
                b = b->next;
            }
        }
        a = a->next;
    }

    /* return list without duplicates */
    return list;
}

A
A
B
C
B
A

A
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C

示例

name.list

包含重复项：

GList *remove_dup (GList *list)
{
    GList *a, *b, *dup;
    a = list;

    /* Pick elements one by one */
    while (a != NULL && a->next != NULL) {
        b = a;

        /* Compare the picked element with rest of the elements */
        while (b->next != NULL) {
            /* If duplicate then delete it */
            if (a->data == b->next->data) {
                /* sequence of steps is important here */
                dup = b->next;
                b->next = b->next->next;
                g_list_free_1 (dup);
            } else  /* This is tricky */ {
                b = b->next;
            }
        }
        a = a->next;
    }

    /* return list without duplicates */
    return list;
}

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A
B
C
B
A

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C

使用后

remove_dup

功能：

name.list = remove_dup (name.list);

name.列表

无重复项：

GList *remove_dup (GList *list)
{
    GList *a, *b, *dup;
    a = list;

    /* Pick elements one by one */
    while (a != NULL && a->next != NULL) {
        b = a;

        /* Compare the picked element with rest of the elements */
        while (b->next != NULL) {
            /* If duplicate then delete it */
            if (a->data == b->next->data) {
                /* sequence of steps is important here */
                dup = b->next;
                b->next = b->next->next;
                g_list_free_1 (dup);
            } else  /* This is tricky */ {
                b = b->next;
            }
        }
        a = a->next;
    }

    /* return list without duplicates */
    return list;
}

A
A
B
C
B
A

A
B
C

->但似乎

remove\u dup

返回相同的

name.list

和重复项

这就是我在这段代码中的错误吗？

这是怎么回事（没有测试过，但应该可以正常工作）：

虽然这个O（n2）函数对于短列表很好，但是对于长列表则效率低下。也许您希望使用不同的算法，如：

GList *remove_dup (GList *list)
{
    GList *a, *dup;
    GHashTable *set;

    set = g_hash_table_new(NULL, NULL);

    /* Pick elements one by one */
    for (a = list; a;) {
        dub = a;
        a = a->next;
        if (g_hash_table_contains(set, dub->data)) {
            list = g_list_delete_link (list, dub);
        } else {
            g_hash_table_add (set, dub->data);
        }
    }

    g_hash_table_unref (set);

    /* return list without duplicates */
    return list;
}

---

请尝试添加比“无效”更准确的问题描述。查找重复数据指针或删除列表节点时是否存在问题？添加了更准确的问题描述