链表的维护（家电营业系统）

本是古典何须时尚 2022-03-26 01:50 157阅读 0赞

读入文件List.txt:

名称 品牌 价格 数量  
phone huawei 2000.000000 35  
clothes supreme 900.000000 8  
shoes lining 800.000000 10  
fan haier 500.000000 5

#include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #define N 15
    typedef struct product
    {
        char name[N];
        char brand[N];
        int amount;
        double price;
        struct product *next;
    }PRO;
    /*生成一个新的节点，并为该节点赋初值，返回指向新节点的指针*/
    PRO *Createnode()
    {
        PRO *p;
        p=(PRO *)malloc(sizeof(PRO));
        if(p==NULL)
        {
            printf("NO enough memory!\n");
            exit(0);
        }
        p->next=NULL;
        strcpy(p->name," ");
        strcpy(p->brand," ");
        p->amount =0;
        p->price=1;
        return p;
    }
    void Insertdata(PRO *head)//用于进货，同时考虑到进同一商品的问题
    {
        PRO *p = head,*s = head,*q;
        p = Createnode();
        printf("请输入进货的名称、品牌、价格和数量：\n");
        scanf("%s %s %lf %d",p->name,p->brand,&p->price,&p->amount);
        if(head->next ==NULL)
        {
            head->next = p;
        }
        else
        {
            while((p->price)<(s->next->price))
            {
                s=s->next;
                if(s->next==NULL)
                {break;}
            }
            if(s->next !=NULL)
            {
                if(strcmp(p->name,s->next->name)==0&&strcmp(p->brand,s->next->brand)==0)
            {
                s->next->amount+=p->amount;
            }
            else
                {
                    q = s->next;
                    s->next = p;
                    p->next = q;
                }
            }
            else
            {
                 s->next = p;
                p->next = NULL;
            }
        }
    }
    void Deletedata(PRO *head)//用于提货，同时考虑到库存不够的问题
    {
        PRO *q = head,*p = head,*s,*r;
        p = Createnode();
        printf("请输入取货的名称、品牌、价格、数量：\n");
        scanf("%s %s %lf %d",p->name,p->brand,&p->price,&p->amount);
        if(head->next==NULL)
        {
            printf("暂无库存！\n");
        }
        else
            {
            while(strcmp(q->next->brand,p->brand)!=0||strcmp(q->next->name,p->name)!=0)
                {
                    q = q->next;
                    if(q->next ==NULL)
                        {break;}
                }
            if(q->next !=NULL)
                {if(q->next->amount == p->amount)
                    {
                        if(q->next->next==NULL)
                        {
                            s = q->next;
                            q->next=NULL;
                            free(s);
                        }
                        else
                        {
                            s = q->next->next;
                            r = q->next;
                            q->next = s;
                            free(r);
                        }
                    }
                    else
                    {
                        if(q->next->amount <p->amount)
                            printf("库存不够！请重新选择操作！\n\n");
                        else
                            q->next->amount -=p->amount;
                    }
                    }
                else
                {
                    if(p->amount==q->amount)
                    {
                        free(q);
                    }
                    else
                    q->amount -=p->amount;
                }
            }
    }
    void Printdata(PRO *head)//打印库存商品信息
    {
        PRO *p=head->next;
        printf("名称\t品牌\t单价\t\t数量:\n");
        while(p!=NULL)
        {
            printf("%s\t%s\t%lf\t%d\n",p->name,p->brand,p->price,p->amount);
            p = p->next;
        }
        printf("\n\n");
    }
    void Updatedata(PRO *head)
    {
        PRO *p,*q=head,*s;
        p = Createnode();
        printf("请输入变动产品的名称、品牌、现价和数量：\n");
        scanf("%s %s %lf %d",p->name,p->brand,&p->price,&p->amount);
        while(strcmp(q->next->brand,p->brand)!=0||strcmp(q->next->name,p->name)!=0)
        {
            q=q->next;
        }
        if(q->next->next==NULL)
        {
            s = q->next;
            q->next = p;
            p->next = NULL;
            free(s);
        }
        else
        {
            s = q->next;
            p->next = s->next;
            q->next = p;
            free(s);
        }
    }
    int Menu()
    {
        int x;
        printf("家电营业系统：\n");
        printf("1.营业开始\n");
        printf("2.进货\n");
        printf("3.提货\n");
        printf("4.更新信息\n");
        printf("5.查询信息\n");
        printf("6.退出系统\n\n");
        printf("请选择你要执行的操作：\n");
        scanf("%d",&x);
        return x;
    }
    void Readfile(PRO *head)//从List.txt中读入数据
    {
        FILE *fp;
        PRO *p=head,*q;
        q=Createnode();
        char name[N],brand[N];
        int price=0,amount=0;
        fp=fopen("List.txt","r");
        if(fp==NULL)
        {
            printf("读取文件List.txt失败！\n");
            exit(0);
        }
        fseek(fp,22,0);
        while(fscanf(fp,"%s",q->name)!=EOF)
        {
            fscanf(fp,"%s",q->brand);
            fscanf(fp,"%lf",&q->price);
            fscanf(fp,"%d\n",&q->amount);
            p->next=q;
            p=q;
            q=Createnode();
        }
        p->next=NULL;
        fclose(fp);
    }
    int Savefile(PRO *head)//保存数据
    {
        FILE *fp;
        PRO *p=head->next;
        fp=fopen("List.txt","w");
        if(fp==NULL)
        {
            printf("写入文件List.txt失败！\n");
            return -1;
        }
        fprintf(fp,"名称\t 品牌\t 价格\t 数量\n");
        while(p!=NULL)
        {
            fprintf(fp,"%s\t %s\t %lf\t %d\n",p->name,p->brand,p->price,p->amount);
            p=p->next;
        }
        fprintf(fp,"\n");
        fclose(fp);
        return 0;
    }
    void Createlist(PRO *head)
    {
        Readfile(head);
        printf("营业开始，请继续选择需要执行的操作：\n");
    }
    int main()
    {
        PRO *head;
        char ch;
        head=Createnode();
        printf("注意：首次进入系统必须选择1号！\n");
        while(1)
        {
            ch = Menu();
            switch(ch)
            {
                case 1:Createlist(head);
                break;
                case 2:Insertdata(head);
                break;
                case 3:Deletedata(head);
                break;
                case 4:Updatedata(head);
                break;
                case 5:Printdata(head);
                break;
                case 6:printf("营业结束！数据已保存至文件！");
                Savefile(head);
                exit(0);
                default:printf("请输入正确序号!\n");
            }
        }
        return 0;
    }