11101

#include <stdio.h>
#include<stdlib.h>
#include<time.h>


typedef struct node
{
    int num;
struct node * next;
}Node;


typedef struct node * Link;


void malloc_ok(Link * new_node)
{
*new_node = (Link)malloc(sizeof(Node));
if(*new_node == NULL)
{
printf("creat error!\n");
exit(-1);
}
}


void create_link(Link * head)
{
malloc_ok(head);
(*head)->next = NULL;
}


void insert_node_head(Link  head,Link new_node)
{
new_node->next = head->next;
head->next = new_node;
}


void insert_node_tail(Link head,Link new_node)
{
Link tmp = head;


while(tmp->next != NULL)
{
tmp = tmp->next;
}
tmp->next = new_node;
new_node->next = NULL;
}


Link find(Link head,int n)
{
    Link tmp = head;
while(tmp != NULL && tmp->num != n)
{
tmp =tmp->next;
}
if(tmp == NULL)
{
printf("can't find this data!\n");
return NULL;
}
else
{
return tmp;
}
}


void display_link(Link head)
{
Link tmp = head->next;
if(head->next == NULL)
{
printf("the link is empty!\n");
}
while(tmp != NULL)
{
printf("num=%d\n",tmp->num);
tmp = tmp->next;
}
}




void delete(Link head,int n)
{
    Link tmp = head->next;
while(tmp->num != n&&tmp->next != NULL)
{
tmp = tmp->next;
}
Link front = head->next;
    if(tmp == head->next)
{
head->next = tmp->next;
free(tmp);
}
else
{
   while(front->next->num != tmp->num)
   {
    front = front->next;
   }
        front->next = tmp->next;
free(tmp);
}
}


void remove_all(Link head)
{
Link tmp = head->next;


if(tmp == NULL)
{
printf("the link is empty!\n");
return;
}
while(tmp->next != NULL)
{
head->next = tmp->next;
free(tmp);
tmp = head->next;
}
free(tmp);


printf("delete success!\n");
}


void insert_node_mid(Link head,Link new_node,int n)
{
Link p1 = NULL;
Link p2 = NULL;


p1 = head->next;
p2 = head;


if(head->next == NULL)//娌℃湁缁撶偣
{
(new_node)->next = NULL;
        head->next = new_node;
}
else
{
while((p1->num < n)&&(p1->next != NULL))
{
p2 =p1;
p1 = p1->next;
}
if(p1->num >= n)
{
new_node->next = p1;
p2->next = new_node;
}
else
{
p1->next = new_node;
(new_node)->next = NULL;
}
}
}


/*void insert_node_mid(Link head,Link *new_node,int n)
{
    Link p1 = NULL;
Link p2 = NULL;


p1 = head->next;
if(p1 == NULL)
{
   head->next = *new_node;
(*new_node)->next = NULL;
}
else
{
   p2 = head;
p1 = head->next;
while(p1 != NULL&&p1->num < n)
{
   p2 = p1;
p1 = p1->next;
}
if(p1 = head->next)
{
   (*new_node)->next = p1;
head->next = *new_node;
}
else
{
   (*new_node)->next = p1;
p2->next = *new_node;
}
}




}*/


void revers_link(Link head)
{
Link p1 = NULL;
Link p2 = NULL;
Link p3 = NULL;


p3 = head->next;


if(p3 == NULL)
{
printf("the link is emtpy!\n");
return;
}


p2 = p3->next;
if(p2 == NULL)
{
return;
}


p1 = p2->next;
if(p1 == NULL)
{
        p2->next = p3;
p3->next = NULL;
head->next = p2;
return;
}


while(p1->next != NULL)
{
p2->next = p3;
p3 = p2;
p2 = p1;
p1 = p1->next;
}
p2->next = p3;
p1->next = p2;
head->next->next = NULL;
head->next = p1;
return;
}


int main()
{
int i;


Link new_node = NULL;
    Link head = NULL;


create_link(&head);


srand(time(NULL));


for(i = 0;i < 10;i++)
{
        malloc_ok(&new_node);
// new_node->num = i;
new_node->num = rand() % 5;
printf("%d ",new_node->num);
// insert_node_tail(head,new_node);
insert_node_mid(head,new_node,new_node->num);
//    insert_node_head(head,new_node);
}
printf("\n");

// find(head,5);
// delete(head,5);


display_link(head);


revers_link(head);
printf("\n");
display_link(head);




remove_all(head);


//display_link(head);


    return 0;
}