单链表的基础实现

#include <stdio.h>
#define LEN sizeof(struct LNode)
#define NULL 0

typedef int ElemType;

struct LNode
{
ElemType data;
struct LNode *next;
};

/*创建一个带空头结点的单链表*/
struct LNode *CreatList()
{
struct LNode *head,*p,*temp;
head = (struct LNode *)malloc(LEN);
p = temp = (struct LNode *)malloc(LEN);
printf("input the number:");
scanf("%d",&p->data);
head->next = p;
while(p->data!=0)
{
p = (struct LNode *)malloc(LEN);
printf("input the number:");
scanf("%d",&p->data);
temp->next = p;
temp = p;
}
temp->next = NULL;
return head;
}

/*打印出单链表*/
void Print(struct LNode *head)
{
struct LNode *p;
p = head->next;

while(p->next!=NULL)
{
printf("%d ",p->data);
p = p->next;
}

}
/*销毁这个线性表*/
void DestroyList(struct LNode *head)
{
struct LNode *p,*temp;
p = temp = head->next;
while(head->next!=NULL)
{
head->next = p->next;
temp = p;
free(temp);
p = head->next;
}
}

/*在第i个位置前插入新结点*/
void InsertList(struct LNode *head,int i)
{
struct LNode *p,*insert;
int count = 0;
p = head;
while(count<i-1 && p)
{
count++;
p = p->next;
}
if(count>i-1 || !p)
return;
printf("input a number that you want to insert:");
insert = (struct LNode *)malloc(LEN);
scanf("%d",&insert->data);
insert->next = p->next;
p->next = insert;
}

/*删除第i个结点*/
void DeleteList(struct LNode *head,int i)
{
struct LNode *p,*temp;
int count = 0;
p = head;
while(count<i-1 && p)
{
count++;
p = p->next;
}
if(count>i-1 || !p)
return;
temp = p->next;
p->next = temp->next;
free(temp);
}

void main()
{
struct LNode *L;
/*创建链表并打印*/
L = CreatList();
printf("your list is:/n");
Print(L);
printf("/n");
/*在第3个结点前插入新结点，并打印*/
InsertList(L,3);
printf("now,your list is:/n");
Print(L);
printf("/n");
/*删除第4个结点，并打印*/
printf("delete the 4th member,");
printf("now,your list is:/n");
/*销毁链表，并验证是否成功*/
DeleteList(L,4);
Print(L);
DestroyList(L);
if(!L->next)
printf("/nyour list has destroyed!");
}