12.9

1.带表头节点的单链表

#include <stdio.h>
#include <stdlib.h>
#define MAN_OK 1
#define MAN_ERR 0 
struct node
{
    int num;
    struct node * next;
};
typedef struct node Node;
typedef struct node * link;


void create_link(link * head)
{
    *head = (link)malloc(sizeof(Node)) ;
    (*head)->next = NULL;
}
int  is_malloc_ok(link * new_node)
{
    if(*new_node == NULL)
    {
        return MAN_ERR;
    }
    else
    {
        return MAN_OK;
    }
}

void create_node(link * new_node,int i)
{ 
    * new_node = (link)malloc(sizeof(Node));
    while(is_malloc_ok(new_node) == NULL)
    {
        *new_node = (link)malloc(sizeof(Node));
    }
    (*new_node)->num = i;

}
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 p;
    p=head;
    while(p->next != NULL)
    {
        p=p->next;
    }
    p->next = new_node;
    new_node->next = NULL;
}
void insert_node_mid(link head, link new_node,int num_loc)
{
    link p, q;
    p=q=head->next;

    if( head->next == NULL)
    {
        printf("link is empty!\n");
        return ;
    }
    while(p->num != num_loc && p->next != NULL)
    {
        q=p;
        p=p->next;
    }
    if( p->next == NULL && p->num != num_loc)
    {
        p->next = new_node;
        new_node->next = NULL;
    }
    else
    {
        if(p == head->next )
        {
            new_node->next = head->next;
            head->next = new_node;
        }
        else
        {
            q->next = new_node;
            new_node->next = p;
        }
    }
}
void detele_node(link head, int num_val)
{
    link p ,q;
    q = p = head->next;

    if( head->next == NULL)
    {
        printf("link is empty!\n");
        return ;
    }
    while(p->num != num_val && p->next != NULL )
    {
        q = p;
        p = p->next;
    }
    if(p->next == NULL && p->num != num_val)
    {
        printf("no such node!\n");
    }
    else
    {
        if( p == head->next)
        {
            head->next = p->next;
            free(p);
        }
        else
        {
            q->next = p->next;
            free(p);
        }
    }
}
void display_node(link head)
{
    link p;
    p=head;
    if( p == NULL)
    {
        printf("link is empty!\n");
    }
    else
    {
        p=head->next;
        while( p->next != NULL)
        {
            printf("num=%d\n",p->num);
            p=p->next;
        }
    }
}
void release_link(link * head)
{
    link p;
    p = *head;

    if(p == NULL)
    {
        printf("link is empty!\n");
    }
    else
    {
        while(p->next != NULL)
        {
            *head = (*head)->next;
            free(p);
            p=*head;
        }
    }
}
int main()
{
    link head = NULL ;
    link new_node = NULL;
    int i;
    int num_val, num_loc;

    create_link(&head);

    
    for(i=0;i<10;i++)
    {
        create_node(&new_node,i);
        insert_node_head(head,new_node);
        //insert_node_tail(head,new_node);
    }
   /* printf("please input loc:");
    scanf("%d",&num_loc);
    printf("please input val:");
    scanf("%d",&num_val);

    create_node(&new_node,num_val);
    insert_node_mid(head,new_node,num_loc);*/

    printf("please input delete val:");
    scanf("%d",&num_val);

    create_node(&new_node,num_val);
    detele_node(head,num_val);

    display_node(head);

    printf("\n\n");
    release_link(&head);
    display_node(head);

    return 0;
}

2.循环链表

#include <stdio.h>
#include <stdlib.h>
#define MAN_ERR 0
#define MAN_OK 1

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

void create_link(link * head)
{
    *head = (link)malloc(sizeof(Node));
    (*head)->next = *head;
}
int is_malloc_ok(link new_node)
{
    if(new_node==NULL)
    {
        printf("link is empty!\n");
        return MAN_ERR;
    }
    else
    {
        return MAN_OK;
    }
}
void create_node(link * new_node, int i)
{
    (*new_node) = (link)malloc(sizeof(Node));
    while(is_malloc_ok(*new_node)==MAN_ERR)
    {
        (*new_node) = (link)malloc(sizeof(Node));
    }
    (*new_node)->num = i;
}
void insert_node_circle(link head, link new_node)
{
    link p;
    p=head;

    while( p->next != head)
    {
        p=p->next;
    }
    p->next = new_node;
    new_node->next = head;
}
void display_link(link head)
{
    link p;
    p=head;

    if( p == NULL)
    {
        printf("link is empty!\n");
    }
    else
    {
        while(p->next != head)
        {
            printf("num=%d\n",(p->next)->num);
            p=p->next;
        }
    }
}
void release_link(link * head)
{
    link p;
    p=*head;

    if( p == NULL)
    {
        printf("link is empty!\n");
    }
    else
    {
        p=(*head)->next;
        while(p != *head)
        {
            (*head)->next = p->next;
            free(p);
            p=(*head)->next;
        }
        free(p);
        *head = NULL;
    }
}
int main()
{
    link head = NULL;
    link new_node = NULL;
    int i, n;

    create_link(&head);

    printf("please input:");
    scanf("%d",&n);

    for(i=1;i<=n;i++)
    {
        create_node(&new_node,i);
        insert_node_circle(head,new_node);
    }

    display_link(head);
    printf("\n\n");
    release_link(&head);
    display_link(head);
    return 0;
}

3.无表头节点链表的倒序

void  fun_link(link * head)
{
    link p1, p2, p3;

    p1=p2=p3=*head;

    if(p1 == NULL)
    {
        printf("link is empty!\n");
        return ;
    }
    if(p1->next == NULL)
    {
        return ;
    }
    p2 = (*head)->next;
    if(p2->next == NULL)
    {
        p2->next = p1;
        p1->next = NULL;
        *head = p2;
        return ;
    }
    p3 = p2->next;
    while(p3->next != NULL)
    {
        p2->next = p1;
        p1=p2;
        p2=p3;
        p3=p3->next;
    }
    p2->next = p1;
    p3->next = p2;

    (*head)->next = NULL ;
    *head = p3;

}