题解 | #KiKi学结构体和指针#

//难绷的数据结构，第一次犯了好多错。写到一半才发现可以有很多更好的选择，自己偏偏选了最难最烦的那一种。
//这就是改屎山的快感吗
#include<stdio.h>
#include<assert.h>
#include<stdlib.h>
//基本元素声明
typedef struct Node {
    int  data;
    struct Node* next;
} Node;
typedef struct Node* List;
//typedef enum bool{ failure = 0,true = 1 } Bool;

//接口声明
List Add(List list, int x);//增加一个节点，并返回该节点地址。
List Delete(List list, int x ,int* s);//删除指定节点，并返回首节点指针。
List findpre(List list,int x);//找到x的先驱元,若x为首元素则返回NULL,未找到也返回空
void pr_list(List list);//遍历链表
void free_List(List list);

//具体实现
int main()
{
    int n = 0;
    scanf("%d", &n);
    List list = NULL;
    int x = 0;
    for (int i = 0; i < n; i++)
    {
        scanf("%d", &x);
        list = Add(list, x);
    }
    //printf("%d",list ->next-> data);
    int m = 0;
    scanf("%d", &m);
    int y=0;
    list = Delete(list, m ,&y);
    //printf("%d",list->next->data);
    printf("%d\n",n-y);
    pr_list(list);
   // printf("\n%d",z);
    free_List(list);

    return 0;
}


//接口定义
List Add(List list, int x)
{
    if (list == NULL)
    {
        list = malloc(sizeof(Node));//创建第一个节点
        if (list == NULL)
        {
            printf("Out of space!");
            return list;
        }
        else
        {
            list->data = x;
            list->next = NULL;
        }
    }
    else
    {
        list->next = Add(list->next, x);
    }

    return list;

}

List findpre(List list,int x)
{
    List listtmp=NULL;
    /*if(list -> data == x)
    {
        //return NULL;
        ;
    }*/
    //else 
    //{
        while(list -> next != NULL)
        {
            if(list -> next -> data == x)
            {
                listtmp = list ;
                break ;
            }
            else 
            {
                list = list -> next;
            }
        //}
        }
        return listtmp;
    
}

List Delete(List list, int x,int* s)
{
    int *y=s;
    List listbox = list;
    List listtmp = NULL;
    if((listtmp=findpre(list , x))!=NULL)
    {
        List listz = NULL;
        while(listtmp != NULL)
        {
            listz = listtmp -> next;
            listtmp -> next = listz -> next;
            free(listz);
            (*y)++;
            listtmp = findpre(listtmp , x);
        }
    }

    //else 
   // {
        list = listbox;
        if (list->data == x)
        {
            (*y)++;
            listtmp = list;
            list = list->next;
            free(listtmp);
        }
   // }
    

    return list;
}

void pr_list(List list)
{
   // int n=0;
    while (list != NULL)
    {
        printf("%d ", list->data);
       // n++;
        list = list->next;
    }
    //return n;

}
void free_List(List list)
{
    List listtmp = NULL;

    while (list != NULL)
    {
        listtmp = list;
        list = list->next;
        free(listtmp);
    }
}