#include<stdio.h>
#include<stdlib.h>
typedef struct link{
int date;
struct link *next;
}link,*linklist;
void print(linklist head)
{
linklist p=head;
while(p !=NULL){
printf("%d ",p->date );
p=p->next ;//让P指向下一个节点
}
printf("\n");
}
linklist delete_list(linklist head,int x)
{
linklist p=head->next ,pr=head;
while(p->next !=NULL){//未到表尾
if(p->date ==x){
if(p==head){//若待删除节点是头结点
head=p->next ;
}else{
pr->next =p->next ;//让前一节点的指针域指向后一节点的指针域
}
free(p);//必须释放待删节点所占用的内存，以防内存泄漏
}else{
pr=p;
p=p->next ;
}
}
print(head);
return head;
}
linklist insert_list(linklist head,int date)
{
linklist p=head,pr=NULL;//pr是新结点的指针
int x;
pr=(linklist)malloc(sizeof(link));
if(pr==NULL){
printf("No enough memory to allocate!\n");
exit(0);
}else{
while(p->next !=NULL){
p=p->next ;
}
p->next =pr;//让末节点的指针指向新节点
}
//输入新的节点的数据
pr->date =date;
pr->next =NULL;
print(head);
scanf("%d",&x);//待在链表中删除的数据
head=delete_list(head,x);
return head;
}
linklist CreatList_NULL(linklist head)
{
link *p=NULL;
p=(linklist)malloc(sizeof(link));
if(p==NULL){
printf("No enough memory to allocate!\n");
exit(0);
}else{
p->next =NULL;
}
return head;
}
linklist CreatList(linklist head)
{
int x,a;
linklist p=NULL,pr=head;
scanf("%d",&x);//每个节点的值
while(x!=-1){
p=(linklist)malloc(sizeof(link));//建立新节点
if(p==NULL){
printf("No enough memory to allocate!\n");
exit(0);
}else{
pr->next=p;
p->date =x;
pr=p;
scanf("%d",&x);
}
}
p->next =NULL;
//创建好了单链表
print(head);
scanf("%d",&a);//待在链表中插入的数据
head=insert_list(head,a);//调用插入函数
return head;
}
void Aver(linklist head)
{
linklist p=head;
int sum=0,count=0;
double aver=0.0;
while(p!=NULL){
sum+=p->date ;
p=p->next ;
count++;
}
aver=1.0*sum/count;
printf("%f",aver);
}
int main()
{
link *head=NULL;
head=CreatList_NULL(head);
head=CreatList(head);
Aver(head);
return 0;
}
