#include <stdio.h>
#include <stdlib.h>

#define USER_MAX 20
//此系統(tǒng)能存放最多的用戶數(shù)

typedef struct
{
 char name[10];
 char password[10];
} User;
//定義一個(gè)存放用戶的結(jié)構(gòu)體

User list[USER_MAX];
//定義一個(gè)全局?jǐn)?shù)組，類型是User,大小是USER_MAX

char* filename = "user.txt";
//需要在你的程序目錄下新建一個(gè)user.txt文件


//登錄函數(shù)
User login()
{
 char name[10];
 char password[10];
 User lg;
 printf("enter name:");
 scanf("%s",name);
 strcpy(lg.name , name);
 printf("enter password:");
 scanf("%s",password);
 strcpy(lg.password,password);
 return lg;
}

//寫(xiě)入txt文件，每一行存在一個(gè)用戶
void writeToFile(User u)
{
 FILE *fw = fopen(filename,"a+");
 fprintf(fw,u.name);
 fprintf(fw,"\t");
 fprintf(fw,u.password);
 fprintf(fw,"\n");
}

//判斷是否存在該用戶
int exist(User u)
{
 int i;
 for(i=0; i<USER_MAX; i++)
 {
 if(0==strcmp(list[i].name ,u.name) && 0==strcmp(list[i].password ,u.password))
 {
 return 1;
 }
 }
 return -1;
}

//注冊(cè)用戶
void registerUser()
{
 char name[10];
 char password[10];
 User user;
 int i;

 printf("enter your name:");
 scanf("%s",name);
 strcpy(user.name , name);

 //判斷注冊(cè)的用戶是否已存在
 for(i=0; i<USER_MAX; i++)
 {
 if(0==strcmp(list[i].name ,name))
 {
 printf("USER ALREADY EXIST");
 return;
 }
 }

 printf("enter your password:");
 scanf("%s",password);
 strcpy(user.password , password);
 writeToFile(user);
}

int menu()
{
 int choice;
 printf("1.login\n");
 printf("2.register\n");
 printf("#.exit\n");
 printf("enter your choice:");
 scanf("%d",&choice);
 return choice;
}




int main()
{
 User test[USER_MAX];
 FILE *fp = fopen(filename,"r");
 int i=0;
 User u;
 if(NULL == fp)
 {
 printf("FILE NOT FOUND");
 return -1;
 }
 for(i=0; i<USER_MAX; i++)
 {
 char uname[10];
 char upassword[10];
 fscanf(fp,"%s%s",uname,upassword);

 strcpy(list[i].name , uname);
 strcpy(list[i].password , upassword);
 }

 int choice = menu();
 if(1 == choice)
 {
 system("cls");
 u=login();
 if(1 == exist(u))
 {
 printf("success");
 }
 else
 {
 printf("WRONG USER OR PASS");
 }

 }
 else if(2 == choice)
 {
 system("cls");
 registerUser();
 }
 else
 {
 return 0;
 }


}