단일 체인 시트 생 성, 삽입, 삭제

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

//1.        
struct node 
{
    int num;
    struct node *next;
};

//    
struct node *creat(struct node *head);
void print(struct node *head);
struct node *del(struct node *head,int num);
struct node *insert(struct node *head,int num,int count);
int n = 0;  //     

int main()
{
    int num = 0,count = 0;
    struct node *head;
    head = NULL;        //2.      

    //  
    printf("************************  **********************
");
    head = creat(head); //     
    print(head);        //     

    //  
    printf("************************  **********************
");
    printf("        :
");
    scanf("%d",&num); 
    printf("num is %d
",num);
    head = del(head,num);
    print(head); 

    //  
    while(1)
    {
        printf("*************************  *********************
");
        printf("         :1---%d:::::",n+1);
        scanf("%d",&count);
        printf("         :");
        scanf("%d",&num);
        head = insert(head,num,count);
        print(head); 
    }
    return 0;
}


//     
struct node *creat(struct node *head)
{
    struct node *p1,*p2;

    //3.  malloc         
    p1 = p2 = (struct node *)malloc(sizeof(struct node)); //    
    printf("    0  ，    0   ，       :p1_addr = %d
",p1);
    scanf("%d",&p1->num);
    p1->next = NULL;
    while(p1->num > 0)
    {
        if(head == NULL)
            head = p1;
        else
            p2->next = p1;
        p2 = p1;

        p1 = (struct node *)malloc(sizeof(struct node));
        p1->next = NULL;//  
        n++;
        printf("    0  ，    0   ，       :p%d_addr = %d
",n,p1);
        scanf("%d",&p1->num);
    }

    free(p1); 
    p1 = NULL;
    p2->next = NULL;
    printf("    
");
    return head;
}

//       
void print(struct node *head)
{

    struct node *tmp;

    tmp = head;

    printf("      !!!
");
    printf("     :%d
",n);
    while(tmp != NULL)
    {
        printf("     :num = %d,   :addr = %d
",tmp->num,tmp);
        tmp = tmp->next;
    }
    printf("      !!!
");
}

//     
struct node *del(struct node *head,int num)
{
    struct node *p1,*p2;

    if(head == NULL)
    {
        printf("      !!!
");
        return head;
    }

    p1 = head;

    //    
    while((num != p1->num) && (p1->next != NULL))
    {
        p2 = p1;         // p1    p2
        p1 = p1->next;   //p1      
    }

    if(p1->num == num)  //     
    {
        if(p1 == head)  // p1    
            head = p1->next;
        else
        {
            p2->next = p1->next;  //     p1       
            free(p1);
        }
        n--;  //    1
    }
    else               //        
    {
        printf("    %d
",num);
    }

    return head;
}

//     
struct node *insert(struct node *head,int num,int count)
{
    struct node *p0,*p1,*p2;

    p1 = (struct node *)malloc(sizeof(struct node));
    p1->num = num;
    p1->next = NULL;

    p0 = head;
    p2 = p0->next;

    //        
    if(count == n + 1)  //    
    {
        while(p0->next != NULL)  //       
        {
            p0 = p0->next;
        }
        p0->next = p1;
    }
    else if(count == 1) //    
    {
        p1->next = head;
        head = p1;
    }
    else
    {
        for(;count > 2;count--)
        {
            p0 = p0->next;
            p2 = p0->next;
        }

        p1->next = p0->next;
        p0->next = p1;
    }
    n++;

    return head;
}