#include <stdio.h>
#include <stdlib.h>
struct node //定义结点的结构体
{
int num;
char name[100];
struct node *next;
struct node *prior;
};
typedef struct node Node; //将struct node简单定义为Node
typedef struct node *Link; //将stcuct node类型定义为*Link
void insert_node_head(Link head, Link new_node) //头插
{
new_node->next = head->next;
new_node->prior = head;
head->next = new_node;
new_node->next->prior = new_node;
}
void insert_node_tail (Link head, Link new_node) //尾插
{
Link p = NULL;
p = head;
while(p->next != head)
{
p = p->next;
}
new_node->next = head;
new_node->prior = p;
p->next = new_node;
new_node->next->prior = new_node;
}
void display_link_next (Link head) //后继输出
{
Link p ;
p = head->next;
if(p == head)
{
printf("Link is empty!\n");
return;
}
while(p != head)
{
printf("num = %d\n",p -> num);
printf("name = %s\n",p -> name);
printf("\n");
p = p -> next; //下一个
}
}
void display_link_prior (Link head) //前驱输出
{
Link p;
p = head->prior;
while(p != head)
{
printf("num = %d\n",p -> num);
printf("name = %s\n",p -> name);
printf("\n");
p = p->prior; //前一个
}
}
void release_link (Link head) //释放链表
{
Link p;
Link q;
p = head->next;
q = head->next;
while(head->next != head)
{
// q = p;
// p = p -> next;
p = head->next;
head->next = (head->next)->next;
// free(q);
free(p);
}
// head->next = head; //使用p、q,在释放完p后,head后就没有指向,则必须加指向NULL,否则会段错误
}
void delete_node (Link head, int number) //删除其中一个结点
{
Link p = NULL;
p = head->next;
if(p == head) //空
{
return;
}
else
{
if(p->num == number) //第一个结点的num满足条件
{
p->next->prior = head;
head->next = p->next;
free(p);
}
else
{
while(p != head && p -> num != number)
{
p = p -> next;
}
if(p == head) //未找到
{
printf("no node!\n");
}
else //删除的结点在中间
{
p->next->prior = p->prior;
p->prior->next = p->next;
free(p);
}
}
}
}
int number_link (Link head) //计算链表长度并返回
{
Link p;
p = head->next;
int num = 0;
while(p != head)
{
p = p -> next;
num++;
}
return num;
}
Link find_link_next (Link head, int n) //查找对应学号所在结点内容,后继
{
Link p;
p = head->next;
while(p -> num != n && p != head)
{
p = p -> next;
}
if(p->num == n)
{
return p;
}
else
{
printf("No find!\n");
return;
}
}
Link find_link_prior (Link head, int n) //查找对应学好所在结点内容,前驱
{
Link p;
p = head->prior;
while(p != head && p->num != n)
{
p = p->prior;
}
if(p->num == n)
{
return p;
}
else
{
printf("No find!\n");
return;
}
}
void enter_link_next (Link head, Link enter_node,int number) //插入新的结点,插在所找结点的前面,后继
{
Link p = NULL;
p = head->next;
while(p != head && p -> num != number)
{
p = p -> next;
}
/*
p->prior->next = enter_node;
enter_node->prior = p->prior;
enter_node->next = p;
p->prior = enter_node;*/
insert_node_head(p, enter_node);
}
void enter_link_prior (Link head, Link enter_node, int number) //插入新的结点,插在所找结点的后面,前驱
{
Link p = NULL;
p = head->prior;
while(p != head && p->num != number)
{
p = p->prior;
}
insert_node_tail(p, enter_node);
}
void search_change_node (Link head, Link change_node, int num) //查找并修改
{
Link p = NULL;
p = head->next;
while(p -> num != num && p != head)
{
p = p -> next;
}
if(p == head)
{
printf("No find!");
return;
}
else
{
enter_link_next(head,change_node,p->next->num);
}
}
void insert_rank_node (Link head, Link new_node) //插入的时候排序
{
Link p = NULL;
p = head->next;
if(p == head) //空
{
head->next = new_node;
new_node -> next = head;
}
else if(p->next == head) //一个结点
{
if(new_node->num > p->num)
{
p->next = new_node;
new_node->next = head;
}
else
{
new_node->next = p;
head->next = new_node;
}
}
else //多个结点
{
if((p->num) > (new_node->num)) //第一个结点的学号大于new_node的学号,大于则new_node插最前面
{
new_node->next = p;
head->next = new_node;
}
else
{
while(p->next != head) //循环到最后一个结点
{
p = p->next;
}
if((p->num) < (new_node->num)) //比较最后一个结点的学号是否小于new_node的学号,小于则new_node插最后
{
p->next = new_node;
new_node->next = head;
}
else
{
p = head->next;
while(((p->next)->num) < (new_node->num)) //查找的结点在中间
{
p = p->next;
}
new_node->next = p->next;
p->next = new_node;
}
}
}
}
Link write_node(Link *new_node) //写入
{
*new_node = (Link)malloc(sizeof( Node )); //创建一个新的结点
if(*new_node == NULL) //检查分配空间
{
printf("malloc error!\n");
exit(-1);
}
}
void create_link(Link * head) //创建头指针,并定义为空指针
{
write_node(head);
(*head)->next = *head;
(*head)->prior = *head;
}
int main()
{
Link head = NULL;
Link new_node = NULL;
Link enter_node = NULL;
Link change_node = NULL;
int i;
int n;
int num;
int number;
create_link(&head);
for(i = 0; i < 3; i++)
{
write_node(&new_node); //写入
scanf("%d",&(new_node)->num); //赋值
scanf("%s", new_node -> name);
// insert_node_head(head, new_node);
insert_node_tail(head, new_node);
// insert_rank_node(head, new_node);
}
display_link_next(head); //输出
/*
num = number_link(head); //返回结点数
printf("number = %d\n", num);
printf("Please input the num, find the name:\n");
scanf("%d",&n);
// printf("%s\n",find_link_next(head, n)->name); // 输出查找号对应的名字
printf("%s\n",find_link_prior(head, n)->name);
printf("\n");
printf("Please input the number of delete:\n");
scanf("%d",&number);
delete_node (head, number); //删除其中一个结点
*/
// flashback_link(head); //倒叙输出
/*
// enter_node = (Link)malloc(sizeof(Node));
printf("Please input the name and number:\n");
write_node(&enter_node);
scanf("%d",&(enter_node->num));
scanf("%s",enter_node->name);
printf("Please input the number of enter:\n");
scanf("%d",&number);
// enter_link_next(head, enter_node, number); //在已经输入的结点里再插入一个新的结点
enter_link_prior(head, enter_node, number);
*/
printf("Please input the number of search and change:");
scanf("%d",&num); //查找的学号
write_node(&change_node);
printf("Please input the number and name:");
scanf("%d",&(change_node->num)); //修改的学号
scanf("%s",change_node->name); //修改的名字
search_change_node(head, change_node, num); //查找并修改
// display_link_next(head); //输出
display_link_prior(head); //输出
release_link (head); //释放
display_link_next(head);
return 0;
}