#define _CRT_SECURE_NO_WARNINGS 1#include
     
      #include
      
       #include
       
        #include
        
         typedef int DataType;typedef struct SListNode{    DataType _data;    struct SListNode* _next;}SListNode;SListNode* _CreateNode(DataType x){    SListNode* head = (SListNode*)malloc(sizeof(SListNode));    head->_data = x;    head->_next = NULL;    return head;}void PushBack(SListNode*& head, DataType x){    if (head == NULL)    {        head = _CreateNode(x);        head->_next = NULL;    }    else    {        SListNode* cur = head;        while (cur->_next != NULL)        {            cur = cur->_next;        }        cur->_next = _CreateNode(x);    }    }void PopBack(SListNode*& head){    if (head == NULL)    {        return;    }     else if (head->_next == NULL)    {        free(head);        head = NULL;    }    else    {        SListNode* cur = head;        SListNode* next = head;        while (cur)        {            next = cur->_next;            if (next != NULL && next->_next == NULL)            {                free(next);                cur->_next = NULL;                return;            }            cur = cur->_next;        }    }    }void PushFront(SListNode*& head,DataType x){    if (head == NULL)    {        head = _CreateNode(x);    }    else    {        SListNode* pcur = _CreateNode(x);        pcur->_next = head;        head = pcur;    }}void PopFront(SListNode*& head){    if (head == NULL)    {        return;    }    else if (head->_next == NULL)    {        free(head);        head = NULL;    }    else    {        SListNode* del = head;        SListNode* next = head->_next;        free(del);        del = NULL;        head = next;    }}void Insert(SListNode* head,int pos,DataType x){    assert(pos >= 0);    SListNode* cur = head;    while (--pos && cur)    {                    cur = cur->_next;            }    if (pos > 0)    {        printf("pos位置大于链表长度!\n");        return;    }    SListNode* newcur = _CreateNode(x);    if (cur->_next)    {        SListNode* next = cur->_next;            cur->_next = newcur;        newcur->_next = next;    }    else if (cur->_next == NULL)    {        cur->_next = newcur;    }}size_t Length(SListNode*& head){    size_t count = 0;    SListNode* cur = head;    while (cur)    {        count++;        cur = cur->_next;    }    return count;}void PrintSList(SListNode*& head){    SListNode* cur = head;    while (cur)    {        printf("%d->", cur->_data);        cur = cur->_next;    }    printf("\n");}void Test(){    SListNode* sList =NULL;    PushBack(sList, 1);    PushBack(sList, 2);    PushBack(sList, 3);    PushBack(sList, 4);    PushBack(sList, 5);    PrintSList(sList);    PopBack(sList);    PrintSList(sList);    PushFront(sList, 0);    PrintSList(sList);    PopFront(sList);    PrintSList(sList);    Insert(sList, 3, 10);    PrintSList(sList);    int ret = Length(sList);    printf("单链表长度为：%d\n", ret);}int main(){    Test();    system("pause");    return 0;}