单链表的实现

#include <stdio.h>#include <stdlib.h>typedef struct list{     int data;     struct list *next;}List;/*function：初始化为带表头的单链表input：voidoutput：List型指针*/List *initList(void){     List *L = (List *)malloc(sizeof(List));     L->data = 0;  //it means this list has o element, and is an empty list     L->next = NULL;     return L;}/*function:从表头插入元素input:待插入的int型数值,链表指针output:null*/void headInsert(int data, List *L){     List *newNode = (List *)malloc(sizeof(List));     newNode->data = data;     newNode->next = NULL;     newNode->next = L->next;     L->next = newNode;     L->data ++;}/*function:display the listinput:链表指针output:void*/void displayList(List *L){     List *p = L;     if(L->next == NULL)     {          printf("This is an empty List\n");          return ;     }     while(p->next != NULL)     {          p = p->next;          printf("%3d",p->data);     }     printf("\n");}/*function:get node at pos position and delete it from the listinput:position and listoutput:elemant with type of int*///pos = 0 means the first data not the head list, so if the list length is n,then the biggest pos is n-1int deleElem(int pos, List *L){     int i = 0;     int value = 0;     List *p = L, *temp = NULL;         if(pos < 0 || pos >= L->data)     {          printf("error: Wrong pos which is not in the list\n");          exit(1);     }     for(i = 0; i < pos; i ++)     {          p = p->next;     }     temp = p->next;     p->next = temp->next;     value = temp->data;     free(temp);     L->data --;     return value;}