#include<stdio.h>#include<stdlib.h>#include<string.h>#define NUM 5struct item{ char brand[20]; char id[10]; float in_price; float out_price; int storage;};struct item_node{ struct item wanted; int amount; struct item_node *next;};int menu();void establish();void dis_all();void shop_cart();int cart_menu();void add();void display();void calculate();struct item goods[NUM];struct item_node *cart;void main(){ printf("***********************************/n"); printf("  歡迎進入超市管理系統/n"); printf("***********************************/n"); while(1) { switch(menu()) { case 1: establish();break; case 2: dis_all();break; case 3: shop_cart();break; case 4: calculate();break; case 5: printf("感謝使用，再見!/n"); exit(0); } }}int menu(){ char str[5]; int select; printf("/n/n請選擇數字進行操作/n"); printf("1.建立庫存信息/n"); printf("2.顯示所有信息/n"); printf("3.購物車/n"); printf("4.結算/n"); printf("5.退出/n"); printf("請選擇對應數字1--5"); while(1) { fflush(stdin); gets(str); select=atoi(str); if(select<1||select>5) printf("輸入錯誤，請重新輸入:"); else break;  } return select; }void dis_all(){ int i; FILE *fp; fp=fopen("goods","r"); for(i=0;(fread(goods+i,sizeof(struct item),1,fp))!=0;i++) { printf("---------------------------------/n"); printf("貨品 品名 單價  庫存量/n"); printf("%s%7s%7.2f%8d/n",goods[i].id,goods[i].brand,goods[i].out_price,goods[i].storage);  } fclose(fp);}void shop_cart(){ while(1) { switch(cart_menu()) { case 1: display();break; case 2: add();break; case 3: return; } }}int cart_menu(){ char str[5]; int select; printf("/n請選擇操作/n"); printf("-----------------------/n"); printf("1.顯示當前購物列表/n"); printf("2.添加商品/n"); printf("3.退出/n"); printf("-----------------------/n/n"); while(1) { fflush(stdin); gets(str); select=atoi(str); if(select<1||select>3) printf("輸入錯誤，請重新輸入:"); else break; } return select;}void display(){ struct item_node *p=cart; if(p==NULL){ printf("購物車為空/n"); return ; } while(p!=NULL){ printf("----------------------------------/n"); printf("貨號    品名 單價 數量/n"); printf("%10s%20s%7.2f%8d/n",p->wanted.id,p->wanted.brand,p->wanted.out_price,p->amount); p=p->next; }}void add(){ FILE *fp; int i,n; char str[20]; char choice1,choice2; struct item_node *p,*p1; do { printf("輸入所需物品的名稱或貨號: "); fflush(stdin); gets(str); if((fp=fopen("goods","r"))==NULL){ printf("打開文件失敗/n"); continue; } for(i=0;fread(goods+i,sizeof(struct item),1,fp)!=0;i++){ if((strcmp(goods[i].brand,str)==0||strcmp(goods[i].id,str)==0)&&goods[i].storage!=0){ printf("已經找到所需物品: /n"); printf("---------------------/n"); printf("貨號 品名 單價 庫存量/n"); printf("%s%6s%3.2f%4d/n",goods[i].id,goods[i].brand,goods[i].out_price,goods[i].storage); printf("請輸入所需數量: "); scanf("%d",&n); if(n>goods[i].storage){  printf("庫存不足/n");  break; } printf("/n是否購買?(Y/N)"); fflush(stdin); choice1=getchar(); if(choice1=='Y'||choice1=='y'){  p1=(struct item_node*)malloc(sizeof(struct item_node));  if(p1==NULL){  printf("內存申請失敗!/n");  exit(1);  }  p1->amount=n;  p1->wanted=goods[i];  p1->next=NULL;  p=cart;  if(cart==NULL)  cart=p1;  else{  while(p->next!=NULL)  p=p->next;  p1->next=p->next;  p->next=p1;  } } break; } } if(i==NUM) printf("未找到所需物品/n"); fclose(fp); printf("是否繼續購物?(Y/N)"); fflush(stdin); choice2=getchar(); }while(choice2=='Y'||choice2=='y');}void establish(){ FILE *fp; int i; printf("請依次輸入貨物信息:/n"); printf("----------------------------/n"); for(i=0;i<NUM;i++) { printf("品名: "); fflush(stdin); gets(goods[i].brand); printf("貨號: "); fflush(stdin); gets(goods[i].id); printf("進價: "); fflush(stdin); scanf("%f",&goods[i].in_price); printf("哨價: "); fflush(stdin); scanf("%f",&goods[i].out_price); printf("數量: "); fflush(stdin); scanf("%d",&goods[i].storage); printf("/n"); } if((fp=fopen("goods","w"))==NULL){ printf("創建文件失敗./n"); return; } fwrite(goods,sizeof(struct item),NUM,fp); fclose(fp);}void calculate(){ float total=0,pay; struct item_node *p; int i; FILE *fp; printf("以下是購物清單: /n"); display(); if((fp=fopen("goods","r"))==NULL){ printf("打開文件失敗: /n"); return; } for(i=0;(fread(goods+i,sizeof(struct item),1,fp))!=0;i++); fclose(fp); p=cart; while(p!=NULL){ total+=p->wanted.out_price*p->amount; for(i=0;strcmp(goods[i].id,p->wanted.id)!=0;i++); goods[i].storage-=p->amount; p=p->next; } printf("總計 %7.2f",total); printf("/n輸入實付金額: "); scanf("%f",&pay); printf("實付:   %7.2f 找零:   %7.2f",pay,pay-total); if((fp=fopen("goods","w"))==NULL){ printf("打開文件失敗./n"); return; } fwrite(goods,sizeof(struct item),NUM,fp); fclose(fp);}