尾插法建立链表--顺序输出

#include
#include
#include

#define OK 0
#define ERROR -1

typedef char elemtype;

typedef struct node {
 elemtype data;
 struct node *next;
}Lnode, *linklist;

linklist tailcreat()
{
 Lnode *h, *p, *t;
 elemtype ch;
 h = (linklist)malloc(sizeof(Lnode));
 h->next = NULL;
 t = h;
 while((ch = getchar()) != '\n')
 {
  p = (linklist)malloc(sizeof(Lnode));
  p->data = ch;
  p->next = NULL;
  t->next = p;
  t = p;
 }
 if(h->next != NULL)
  return h;
 else
  return NULL;
}

//取元素
//读取单链表中第i个元素，1<=i<=length(h)
elemtype get(linklist h, int i)
{
 int j = 1;
 Lnode *p;
 p = h->next;
 while(p && j < i)//移动p，直到p为空，或者j < i
 {
  p = p->next;
  j++;
 }

 if((p != NULL) && j == i)
  return (p->data);
 else
  return ERROR;
}
//删除元素
//删除i元素，并返回其值，1<=i<=length(h)  
elemtype delete(linklist h, int i)
{
 int j = 1;
 elemtype e;
 Lnode *p, *q;
 p = h->next;
 while((p->next != NULL)&& j < i-1)
 {
  p = p->next;
  j++;
 }
 if((p->next != NULL) && j == i-1)
 {
  q = p->next;
  p->next = q->next;
  e = q->data;
  free(q);
  return e;
 }
 else
  return ERROR;
}
//插入元素
//第i个元素之前插入一个元素
int insert(Lnode *h, int i, elemtype x)
{
 Lnode *p, *s;
 p = h->next;
 int j = 1;
 while(p && j < i - 1)//寻找第i－1个结点
 {
  p = p->next;
  j++;
 }
 if(p && j == i- 1)
 {
  s = (Lnode *)malloc(sizeof(Lnode));
  s->next = p->next;
  p->next = s;
  s->data = x;
  return OK;
 }
 else
  return ERROR;
}

//主程序

#include"lklist_1.c"

int main()
{
 linklist taillist;
 int j = 1, count;
 taillist = tailcreat();
 printf("请输入所创建链表的元素个数：");
 scanf("%d", &count);
 printf("取单链表中第2个元素：");
 printf("%c\n",get(taillist, 2));
 printf("删除单链表中第3个元素：");
 printf("%c\n",delete(taillist, 3));
 printf("在链表中第3个元素之前插入c.\n");
 insert(taillist, 3, 'c');
 printf("依次输出单链表中的元素：");
 for(j = 1; j < count + 1; j++)
 {
  printf("%c",get(taillist, j));
 }
 printf("\n");
 return 0;
}