链表

记录一下 这几天总结的用C语言写的链表的一下操作：

//准备工作

/* 定义一个表示链表的结构体指针 */
struct list {
    int id;            /* 标识这个元素方便查找 */
    int data;        /* 链表中包含的元素 */
    struct list *next;    /* 指向下一个链表的指针 */
};

/* 定义一个链表头部 */
static struct list *list_head = NULL;
static struct list *list_head1 = NULL;

/* 为了保证每一个链表元素的id不同，特意把id定义成一个全局静态变量 */
static int list_id = 0;

//添加

static void list_add(struct list **head, struct list *list)
{
    struct list *temp;
    
    /* 判断链表是否为空 */
    if(NULL == *head)
    {
        /* 为空 */
        *head = list;
        (*head)->next = NULL;
    }
    else
    {
        /* 不为空 */
        temp = *head;
        while(temp)
        {
            if(NULL == temp->next)
            {
                temp->next = list;
                list->next = NULL;
            }
            temp = temp->next;
        }
    }
}

 

 

 

//输出

static void list_print(struct list **head)
{
    struct list *temp;
    
    temp = *head;
    
    printf("list information :\n");
    while(temp)
    {
        printf("\tlist %d : %d\n", temp->id, temp->data);
        temp = temp->next;
    }
}

 

 

//main

    int i = 0;
    struct list *lists = NULL;//创建一个空表

    /* 分配10个元素 */
    lists = (struct list*)malloc(sizeof(struct list) * 5);
    if(NULL == lists)
    {
        printf("malloc error!\n");
        //        return -1;
    }

    int arr[5] = {1,4,3,5,2};
    //    char* arr = new char[5]{1,4,2,5,3};
    /* 将分配的10个元素依次填充数据并加入到链表当中 */
    for(i = 0; i < 5; i++)
    {
        lists[i].id = list_id++;
        //        sprintf(lists[i].data, "%d",arr[i]);
        lists[i].data = arr[i];
        list_add(&list_head, &lists[i]);
    }
    //    for(i = 0; i < 10; i++)
    //    {
    //        lists[i].id = list_id++;
    ////        sprintf(lists[i].data, "TECH-PRO - %d", i);
    //        lists[i].data = i;
    //        list_add(&list_head, &lists[i]);
    //    }



    /* 遍历链表，把链表中每个元素的信息都打印出来 */
    list_print(&list_head);

 

 

 

 

//反转


static void list_reverse(struct list **head)
{
    struct list *temp = *head;;
    list *prev = NULL;
    
    list *next;
    while(temp != NULL)
    {
        next = temp->next;
        temp->next = prev;
        prev = temp;
        temp = next;
    }
    *head = prev;
}

 

 

 

 

//升序排序

void swap(int *a,int *b){
    int t=*a;
    *a=*b;
    *b=t;
}
list *partion(list *left,list *right){
    if(left==right||left->next==right)    return left;
    int key = left->data;    //选择pBegin作为基准元素
    list *p=left,*q=left;
    while(q!=right){   //从pBegin开始向后进行一次遍历
        if(q->data < key){
            p=p->next;
            swap(&p->data,&q->data);
        }
        q=q->next;
    }
    swap(&p->data,&left->data);
    return p;
}
void quick_sort(list *left,list *right){
    if(left==right||left->next==right)    return;
    list *mid=partion(left,right);
    quick_sort(left,mid);
    quick_sort(mid->next,right);
}
list * sortList(list* head) {
    if(head==NULL||head->next==NULL)    return head;
    quick_sort(head,NULL);
    return head;
}

 

 

 

//创建一个有环的单链表

list * CreatListTail(list * L, int n){
    
    list *p,*r;
    int i;
    
    srand(time(0));                            /* 初始化随机数种子 */
    L = (struct list*)malloc(sizeof(struct list));        /* L为整个线性表 */
    r = L;                                   /* r为指向尾部的结点 */
    
    for (i = 0; i < n; i++) {
        
        p = (struct list*)malloc(sizeof(struct list));      /* 生成新节点 */
        p->data = rand()%100 +1;               /* 随机生成100以内的数字 */
        r->next = p;                          /* 将表尾终端结点的指针指针指向新节点 */
        r = p;                                /* 将当前的新节点定义为表尾终端结点 */
    }
    
    r->next = (L)->next->next;                /* 尾部指向第二个结点(如果无环r->next = null) */
    
    return r;
}

 

//判断链表是否有环

int testLinkRing(list *head)
{
    list *t1 = head, *t2 = head;
    while(t1->next && t2->next)
    {
        t1 = t1->next;
        if (NULL == (t2 = t2->next->next))
            return 0;    //无环
        if (t1 == t2)
            return 1;
    }
    return 0;
}

 

 

 

//合并两个有序的单链表(递归)

list* Merge2(list* head1, list* head2)
{
    list* res;
    if(head1 == NULL) return head2;
    if(head2 == NULL) return head1;
    if(head1->data < head2->data)
    {
        res = head1;
        res->next = Merge2(head1->next, head2);
    }
    else
    {
        res = head2;
        res->next = Merge2(head1, head2->next);
    }
    return res;
}

 

//main  

  struct list *firstList = NULL;//创建一个空表
    firstList = (struct list*)malloc(sizeof(struct list) * 5);
    int firstArr[5] = {2,4,6,8,10};
    for(i = 0; i < 5; i++)
    {
        firstList[i].id = list_id++;
        firstList[i].data = firstArr[i];
        list_add(&list_head, &firstList[i]);
    }

    struct list *secondLists = NULL;//创建一个空表
    secondLists = (struct list*)malloc(sizeof(struct list) * 5);
    int secondArr[5] = {1,3,5,7,9};
    for(i = 0; i < 5; i++)
    {
        secondLists[i].id = list_id++;
        secondLists[i].data = secondArr[i];
        list_add(&list_head1, &secondLists[i]);
    }

    list_print(&list_head);
    list_print(&list_head1);

    struct list *mergeLists1 = NULL;//创建一个空表
    mergeLists1 = (struct list*)malloc(sizeof(struct list) * 5);
    mergeLists1 = Merge2(list_head, list_head1);
    NSLog(@"11111111111111------------------------");
    list_print(&mergeLists1);
    NSLog(@"222222222222222------------------------");