链表

#include <stdio.h>

#include <stdlib.h>

struct node

{

int num;

struct node * next;

};

typedef struct node Node;

typedef struct node * Link;

void create_link(Link * head)

{

*head = NULL;

}

void insert_node_head(Link * head,Link new_node)

{

    new_node->next = *head;

*head = new_node;

}

void display_node(Link head)

{

Link tmp;

tmp = head;

if(head == NULL)

{

printf("link is empty!\n");

return;

}

while(tmp != NULL)

{

printf("num = %d\n",tmp->num);

tmp = tmp->next;

}

}

void is_malloc_ok(Link new_node)

{

     if(new_node == NULL)

{

printf("malloc error!\n");

exit(-1);

}

}

void create_newnode(Link * new_node)

{

*new_node = (Link) malloc(sizeof(Node));

is_malloc_ok(*new_node);

}

void insert_node_tail(Link *head,Link new_node)

{

    Link tmp;

tmp = *head;

if(*head == NULL)

{

new_node->next = *head;

*head = new_node;

}

else 

{

while(tmp->next != NULL)

{

tmp = tmp->next;

}

tmp->next = new_node;

new_node->next = NULL;

}

}

void insert_node_mid(Link *head,Link new_node,int num)

{

    Link tmp;

tmp = *head;

    

if(NULL == *head)

{

printf("link is empty!\n");

return;

}

else

{

    while(tmp->num != num && tmp->next != NULL)

    {

            tmp = tmp->next;

    }

        if(tmp->num == num)

{

            new_node->next = tmp->next;

tmp->next = new_node;

}

else

{

printf("no such node!\n");

}

}

}

void insert_node_mider(Link * head,Link * new_node,int num)

{

Link p1 = NULL;

Link p2 = NULL;

p1 = *head;

if(*head == NULL)

{

(*new_node)->next = *head;

*head = *new_node;

}

else

{

while((p0->num < num) && (p1->next != NULL))

{

p2 = p1;

p1 = p1->next;

}

if((*head)->next == NULL)

{

if(num < p1->num)

{

(*new_node)->next = *head;

*head = *new_node;

}

else

{

(*head)->next = *new_node;

(*new_node)->next = NULL;

}

}

else

{

if(p1 == *head)

{

  (*new_node)->next = *head;

*head = *new_node;

}

else

{

if(p1->next != NULL)

{

  p2->next = *new_node;

(*new_node)->next = p1;

}

else

{

if(num > p1->num)

{

p2 = p1->next;

p1->next = *new_node;

(*new_node)->next = p2;

}

else

{

  p2->next = *new_node;

(*new_node)->next = p1;

}

}

}

}

}

}

void revers_link(Link * head)

{

Link p1 = NULL;

Link p2 = NULL;

Link p3 = NULL;

p3 = *head;

if(*head == NULL)

{

printf("link is empty!\n");

return;

}

if(p3->next == NULL)

{

return;

}

p2 = p3->next;

if(p2->next == NULL)

{

p2->next = p3;

p3->next = NULL;

*head = p2;

return;

}

p1 = p2->next;

while(p1->next != NULL)

{

   p2->next = p3;

p3 = p2;

p2 = p1;

p1 = p1->next;

}

p1->next = p2;

p2->next = p3;

(*head)->next = NULL;

*head = p1;

return;

}

void delete_node(Link *head,int num)

{

Link tmp;

Link p;

tmp = p = *head;

if(NULL == *head)

{

printf("link is empty!\n");

return;

}

while(tmp->num != num && tmp->next != NULL)

{

p = tmp;

tmp = tmp->next;

}

if(tmp->num == num)

{

        if(tmp == *head)

{

            *head = tmp->next;

free(tmp);

}

else

{

p->next = tmp->next;

free(tmp);

}

}

else

{

printf("no such node!\n");

}

}

void release_link(Link * head)

{

    Link tmp;

tmp = *head;

if(NULL == *head)

{

printf("link is empty!\n");

return ;

}

while(*head != NULL)

{

tmp = *head;

   *head = (*head) -> next;

free(tmp);

}

printf("release succse!\n");

}

int main()

{

    Link head = NULL;

    Link new_node = NULL;

    int i;

int num;

create_link(&head);

for(i = 0; i < 10;i++)

{

        create_newnode(&new_node);

// scanf("%d",&new_node);

// insert_node_mider(&head,&new_node,10);

new_node->num = i;

// insert_node_head(&head,new_node);

insert_node_tail(&head,new_node);

}

// printf("please input a num!\n");

// scanf("%d",&num);

// create_newnode(&new_node);

// new_node->num =  num;

// insert_node_mid(&head,new_node,10);

    display_node(head);

// delete_node(&head,num);

//    release_link(&head);

    revers_link(&head);

display_node(head);

    //release_link(&head);

    return 0;

}