820 C语言 作业

#include <stdio.h>


void main()
{
    int i,j;
    int code=0,flag=0;
    int choice1=0,choice2=0,choice3=0;
    int RMB=100000,WB=100000;
    int cash1=0,cash2=0;
    char instruct='n';
    
    printf("************************************************************\n");
    printf("*                                                          *\n");
    printf("*               欢迎使用blue shit ATM取款机                *\n");
    printf("*                                                          *\n");
    printf("*                                  version number:1.0.1    *\n");
    printf("*                                                          *\n");
    printf("************************************************************\n");
    
    printf("请键入您的密码：\n");
    
    
    for(i=0;i<3;i++)
    {
        scanf("%d",&code);
        system("cls");
        if(code==9527)
        {
            break;
        }
        if(code!=9527)
        {
            printf("密码有误！请再次输入：\n");
            flag+=1;
        }
     }
     if(flag==3)
        {
            printf("您的密码输入错误3次，请到blue shit咨询！");
            return; 
        }     
             
    while(instruct=='N'|| instruct=='n' )
    {
         
         if(code==9527)
         {
             printf("徐先生，欢迎回来！\n");
             printf("1.查询余额   2.取款   3.退出");
              scanf("%d",&choice1);
              system("cls");
             switch(choice1)
             {
                   case 1:printf("1.人民币  2.外币");
                       scanf("%d",&choice2);
                       system("cls");
               
                       switch(choice2)
                       {
                           case 1:printf("您的人民币账户余额：￥%d\n",RMB);
                                  break;
                                        
                           case 2:printf("您的外币账户余额：$%d\n",WB);
                                  break;
                       }
                       break;
                           
                case 2:printf("1.人民币  2.外币");
                       scanf("%d",&choice3);
                       system("cls");
                                 
                       switch(choice3)
                       {
                            case 1:printf("请输入取款额度：\n");
                                   scanf("%d",&cash1);
                                               
                                   RMB=RMB-cash1;
                                   printf("您的账户余额：￥%d\n",RMB);
                                   break;
                         
                            case 2:printf("请输入取款额度：\n");
                                   scanf("%d",&cash2);
                                               
                                   WB=WB-cash2;
                                   printf("您的账户余额：$%d\n",WB);
                                   break;
                           }
                           break;
                 case 3:
                        break;          
                           
               }
               printf("是否退出程序<y表示是，n表示否>：");

               scanf("%s",&instruct);     
          }
          
    
    }
}