c语言练习题 ATM机流程

自学c语言自娱自乐的，看到有的练习题上有模拟ATM机流程的练习就试着写了一个。

#include
#include


int userpassword;
int remaind;


void welcome();
void end();
int  start();
void password();
void loadin();
void leftcount();
void getmoney();
void savemoney();



void welcome()
{
    printf("******************************\n");
    printf("*   welcome use kirito ATM   *\n");
    printf("*      password 819821       *\n");
    printf("*                            *\n");
    printf("*   any key to continue...   *\n");
    printf("******************************\n");
    getch();
    system("cls");
}

void end()
{   
    system("cls");
    printf("******************************\n");
    printf("*         kirito ATM         *\n");
    printf("*                            *\n");
    printf("*                            *\n");
    printf("*       any key to end...    *\n");
    printf("******************************\n");
    getch();
    exit(0);
}

int start()
{   
    int z;
    do
    {
        system("cls");
        printf("******************************\n");
        printf("*     please select key:     *\n");
        printf("*       1. password          *\n");
        printf("*       2. remaind           *\n");
        printf("*       3. getmoney          *\n");
        printf("*       4. savemoney         *\n");
        printf("*       5. Return            *\n");
        printf("******************************\n");
        scanf("%d",&z);
    }
    while(z!=1 && z!=2 && z!=3 && z!=4 && z!=5);
    return z;
}

void loadin()
{
    int i,password;
    i = 0;
    system("cls");
    printf("input password:\n");/*验证密码*/
    scanf("%d",&password);
    while(password != userpassword)/*验证密码，三次后系统退出*/
    {
        i++;
        system("cls");
        if(i==1 || i==2) 
            printf("Wrong password,input again\n");
        if(i == 3) 
        {
            printf("Wrong Password,System Close!");
            Sleep(2000);
            end();
        }
        scanf("%d",&password);
    }
}

void password()
{   int key;
    int password;
    int newpassword1,newpassword2;
    loadin();/*验证密码*/
    do{

        system("cls");
        printf("******************************\n");
        printf("*     please select key:     *\n");
        printf("*     1. change password     *\n");
        printf("*     2. Return              *\n");
        printf("*                            *\n");
        printf("******************************\n");
        scanf("%d",&key);
    }
    while(key != 1 && key != 2);
    switch(key)
    {
        case 1 : 
        {
            do
            {
                system("cls");
                printf("input new password:\n");
                scanf("%d",&newpassword1);
                system("cls");
                printf("input new password again:\n");
                scanf("%d",&newpassword2);
                system("cls");
                if(newpassword1 != newpassword2)
                    {
                        printf("diffrent password,try again.");
                        Sleep(2000);
                    }
            }while(newpassword1 != newpassword2);/*循环体内保证两次输入新密码一致*/

            userpassword = newpassword1;
            printf("new password change success!\n"); 
            Sleep(2000);

        };break; 
        case 2 : break;
    }

}


void leftcount()
{   
    loadin();/*验证密码*/
    printf("remaind : %d\n",remaind);
    getch();
}

void getmoney()
{   int key;
    int t;
    loadin();/*验证密码*/
    while(1)
    {
        do
        {   
            system("cls");
            printf("******************************\n");
            printf("*         1. 100             *\n");
            printf("*         2. 500             *\n");
            printf("*         3. 1000            *\n");
            printf("*         4. return          *\n");
            printf("******************************\n");
            scanf("%d",&key);
        }
        while(key!=1 && key!=2 && key!=3 && key!=4);

        switch(key)
        {   
            case 1 : 
                {   system("cls");
                    if(remaind >= 100) 
                        {   printf("take your money.\n");
                            remaind = remaind - 100;
                            printf("remaind : %d\n",remaind);   
                        }
                    else printf("no enough remaind.\n");            
                };break;
            case 2 : 
                {   system("cls");
                    if(remaind >= 500) 
                        {   printf("take your money.\n");
                            remaind = remaind - 500;
                            printf("remaind : %d\n",remaind);                           
                        }
                    else printf("no enough remaind.\n");            
                };break;
            case 3 : 
                {   system("cls");
                    if(remaind >= 1000) 
                        {   printf("take your money.\n");
                            remaind = remaind - 1000;
                            printf("remaind : %d\n",remaind);                           
                        }
                    else printf("no enough remaind.\n");            
                };break;                
            default : break;        
        }
        printf("1:continue or 2:return\n");
        scanf("%d",&t);
        if(t!=1) break;
    }       
}
void savemoney()
{
    int key;
    int t;
    loadin();
    while(1)
    {    
        do
        {   
            system("cls");
            printf("******************************\n");
            printf("*         1. 100             *\n");
            printf("*         2. 500             *\n");
            printf("*         3. 1000            *\n");
            printf("*         4. return          *\n");
            printf("******************************\n");
            scanf("%d",&key);
        }
        while(key!=1 && key!=2 && key!=3 && key!=4);

        switch(key)
        {   
            case 1 : 
                {   system("cls");
                    remaind = remaind + 100;
                    printf("remaind : %d\n",remaind);                   
                };break;
            case 2 : 
                {   system("cls");
                    remaind = remaind + 500;
                    printf("remaind : %d\n",remaind);                               
                };break;
            case 3 : 
                {   system("cls");
                    remaind = remaind + 1000;
                    printf("remaind : %d\n",remaind);                               
                };break;            
            default : break;        
        }
        printf("1:continue or 2:return\n");
        scanf("%d",&t);
        if(t!=1) break;             
    }   
} 
int main()
{
    int key;
    userpassword = 819821;
    remaind = 10000;
    system("title ATM@kirito");
    system("mode con cols=35 lines=10");
    welcome();
    while(1)
    {
        key = start();
        switch(key)
        {
            case 1 : password();break;
            case 2 : leftcount();break;
            case 3 : getmoney();break;
            case 4 : savemoney();break;
            case 5 : end();         
        }
    }
    return 0;
}