考研数据结构与算法----单链表的创建和读取（2）

#include<stdio.h>
#include<stdlib.h>
#define OK 1
#define ERROR 0
#define TRUE 1
#define FALSE 0
typedef int Status;
typedef int ElemType;
typedef struct Node
{
ElemType data;
struct Node *next;
}Node;
typedef struct Node *LinkList;
Status GetElem(LinkList L, int i, ElemType *e);
Status ListInsert(LinkList *L, int i, ElemType e);
Status ListDelete(LinkList *L, int i, ElemType *e);
Status InitList(LinkList *L, int n);
Status FreeList(LinkList *L);
void ShowList(LinkList L);
int main(void)
{
LinkList myList;
InitList(&myList, 9);
ElemType t;
GetElem(myList, 1, &t);
printf("%d",t);
printf("\n");
ShowList(myList);
ListInsert(&myList, 3, 99);
ShowList(myList);
ListDelete(&myList, 10, &t);
ShowList(myList);
FreeList(&myList);
system("pause");
}

Status GetElem(LinkList L, int i, ElemType *e)
{
int j = 1;
LinkList p;
p = L->next;
while(p && j<i)
{
p = p->next;
j++;
}
if(!p || j>i)
{
return ERROR;
}
*e = p->data;
return OK;
}
Status ListInsert(LinkList *L, int i, ElemType e)
{
int j = 1;
LinkList p,s;
p = *L;
while(p&&j<i)
{
p = p->next;
j++;
}
if(!p||j>i)
{
return ERROR;
}
s = (LinkList)malloc(sizeof(Node));
s->data = e;
s->next = p->next;
p->next = s;
return OK;
}
Status InitList(LinkList *L, int n)
{
LinkList p,r;
int i;
*L =(Node *)malloc(sizeof(Node));
r = *L;
for(i=0; i<=n; i++)
{
p = (Node*)malloc(sizeof(Node));
p->data = i+1;
r->next = p;
r = p;
}
r->next = NULL;
return OK;
}
void ShowList(LinkList L)
{
LinkList p;
p = L->next;
while(p->next)
{
printf("%d\t", p->data);
p = p->next;
}
printf("\n");
}
Status ListDelete(LinkList *L, int i, ElemType *e)
{
LinkList p,s;
p = *L;
int j = 1;
while(j<i && p->next)
{
p = p->next;
j++;
}
if( (!p->next) || j>i )
return ERROR;
s = p->next;
p->next = s->next;
*e = s->data;
free(s);
return OK;
}
Status FreeList(LinkList *L)
{
LinkList p,q;
p = (*L)->next;
while(p)
{
q = p->next;
free(p);
p = q;
}
(*L)->next = NULL;
return OK;
}