数据结构---无重复元素链表的实现

//节点结构体
struct inv
{
    int i;//节点元素
    struct inv*nextpointer;
};



//返回指定元素节点的指针，不包含时返回NULL
struct inv*  contain(int i,struct inv*head)
{
    struct inv *headp=head;
    while(headp!=NULL)
    {
        if(headp->i==i)
        {
            break;
        }
        headp=headp->nextpointer;
    }
    return headp;
}


//追加元素
int append(int i,struct inv **headpp)
{
    struct inv *headp=*headpp;
    struct inv *prev;
    if(*headpp==NULL)
    {
        *headpp=(struct inv*)malloc(sizeof(struct inv));
        (*headpp)->i=i;
        (*headpp)->nextpointer=NULL;
        return 1;
    }


    while(headp!=NULL)
    {
        prev=headp;        
        if(headp->i==i)
        {
            return 0;
        }
        headp=headp->nextpointer;
    }


    prev->nextpointer=(struct inv*)malloc(sizeof(struct inv));
    prev=prev->nextpointer;

    prev->i=i;
    prev->nextpointer=NULL;
    
    return 1;

}



//删除指定元素
int dele(int i,struct inv **headpp)
{
    int returnvalue=0;
    struct inv*prev;
    struct inv*headp=*headpp;

    if(headp==NULL)
    {
        return 0;
    }

    while(headp->i!=i&&headp->nextpointer!=NULL)
    {
        prev=headp;
        headp=headp->nextpointer;
    }
    if(headp->i==i)
    {
        if(headp==*headpp)
        {
            *headp=*headp->nextpointer;
        }
        prev->nextpointer=headp->nextpointer;
        free(headp);
        return 1;

    }
    return 0;
}



//删除整个链表
void deleteall(struct inv**head)
{
    struct inv*headp=*head;
    struct inv*temp;
    while(headp!=NULL)
    {
        temp=headp->nextpointer;
        free(headp);
        headp=temp;
    }
    *head=NULL;
}



//扫描打印
void paint(struct inv*headp)
{
    while(headp!=NULL)
    {
        printf("    %d\n",headp->i);
        headp=headp->nextpointer;
    }
}