嵌套单链表 c 的显示函数

Question

我正在为我的 c 类编写数据库程序几天，现在我试图弄清楚如何使用单链表，我会说它很难理解，至少对我来说是这样。总的来说，我得到了我的项目所需的部分代码，基本上我得到了向客户端添加客户端和项目的功能，这要归功于 stackoverflow 某人的帮助我到底可以打印它，尝试按照您可以看到我的显示功能的方式进行打印，但它不适用于链接到客户端的项目我应该更改什么才能使其正常工作？

#include <stdio.h>
#include <stdlib.h>
struct item{
char item_name[30];
struct item *NextItem;
};
struct client{
    struct client *NextClient;
    char name[30];
    char last_name[30];
    struct item *firstItem;
  struct item *lastItem;
};
struct client *head = NULL;
/////////////////////////////
struct client* FindTailClient(struct client* head)
{
    struct client *temp = head;
    while( temp->NextClient != NULL)
    {

       temp = temp->NextClient;
    }
    return temp;
}
/////////////////////////////
////////
 struct client *GetClientData()
  {
      char data[30];
    struct client *temp;
    temp = (struct client*)malloc(sizeof(struct client));

    printf("Enter the person's name--->");
    scanf("%s",data);
    strcpy(temp->name,data);
    printf("Enter the person's last name--->");
    scanf("%s",data);
    strcpy(temp->last_name,data);
    temp->NextClient = NULL;
    return temp;
  }
///////////
struct item *GetItemData()
  {
    struct item *temp;
    char data[30];
    temp = (struct item*)malloc(sizeof(struct item));

    printf("Enter the item name--->");
    scanf("%s",data);
    strcpy(temp->item_name,data);
    temp->NextItem = NULL;
    return temp;
  }
///////////
//////////////
struct client* AddClient()
{
  struct client *temp,temp1;
  temp=head;
  struct client *data = GetClientData();



  if(head == NULL)
  {
      head=data;
      head->NextClient = NULL;
  }
  else
  {
     while(temp->NextClient != NULL)
     {
     temp=temp->NextClient;
     }
     data->NextClient=NULL;
     temp->NextClient=data;
  }
}
///////////////////

///////////////////

///////////////////
void display()
{
    struct client *CurrentClient = head;
struct item *ItemCurrent = head->firstItem;
      while(CurrentClient != NULL)
      {
        printf(" -> %s ->%s \n",CurrentClient->name,CurrentClient->last_name);
               while(ItemCurrent != NULL)
               {
               printf(" -> %s\n",ItemCurrent->item_name);
               ItemCurrent=ItemCurrent->NextItem;
               }
      CurrentClient=CurrentClient->NextClient;
      }

}
///////////////////
void AddItemToClient(struct client* head, struct item *item)
{
    item->NextItem = NULL;
    if(head->firstItem == NULL) {
        head->firstItem = item;
    } else {
        head->lastItem->NextItem = item;
    }
    head->lastItem = item;

}
///////////////////
struct client *find(struct client *head, char name[])
{
    while (head->NextClient != NULL )
    {
        if (strcmp(head->name,name) == 0)
        {
            printf("Target found: %s\n",head->name);
            return head;
        }
        head = head->NextClient;
    }
    printf("target not found");
    return NULL;
}
//////////////////
int main()
{
    int i;
    char data[30];
    char name[30];
    struct client *temp;
    struct client *head;
    struct item *data1;
    for(i=0;i<2;i++)
    {
    AddClient();
    }
    printf("Insert name to find:");
    scanf("%s",name);
temp = find(&head,name);
data1 = GetItemData();
AddItemToClient(temp,&data1);
display();
}

Answer 1

在这一行中：“while(ItemCurrent != ItemLast)” - ItemLast 未声明。也许你想写 head->lastItem，或者更好的 ItemCurrent->next != NULL。 此外，请确保您存储了刚刚创建的客户端以便能够访问它们：head = AddClient();而不是简单的 AddClient();