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

char user[5][25],pass[5][25],again;
char logUser[25],logPass[25],New[25],change;
int data=0,choose,i;

void regis();
void login();
void list();
void update(int x);

int main(){
    printf("~~~WELCOME~~~");
    list();
    return 0;
}

void regis(){
    if(data==5){
        printf("\nAccount Has Been Full\n");
        login();
    }else{
    printf("Registration\n");
    fflush(stdin);
    printf("Enter The Username: ");
    gets(user[data]);
    printf("Enter The Password: ");
    gets(pass[data]);
    data++;
    printf("\nRegister Again? [Y]/[N]: ");
    scanf("%c",&again);
    if(again=='Y'||again=='y'){
        regis();
    }else{
        list();
    }
    }
}

void login(){
    printf("\nLogin: \n");
    fflush(stdin);
    printf("Enter The Username: ");
    gets(logUser);
    printf("Enter The Password: ");
    gets(logPass);
    for(i = 0;i < data; i++){
        if(strcmp(logUser,user[i])==0){
            if(strcmp(logPass,pass[i])==0){
                printf("\nLogin Succesfuly\n");
                printf("Change Password [Y/N] ? ");
                scanf("%c",&change);
                if(change == 'y' || change == 'Y'){
                    update(i);
                    break;
                }else{
                    list();
                    break;
                }
            break;
            }else{
                printf("Login Failed\n");
                list();
                break;
            }
        }else{
            continue;
        }
    }
}

void list(){
    printf("\n1. REGISTER \n2. LOGIN \n3. EXIT PROGRAM");
    printf("\nChoose: ");
    scanf("%d",&choose);
    if(choose==1){
        regis();
    }else if(choose==2){
        login();
    }else{
        printf("\n~~~Thank You~~~\n");
        exit(1);
    }
}

void update(int x){
    fflush(stdin);
    printf("Enter The New Password: ");
    gets(New);
    strcpy(pass[x], New);
    printf("Password Has Benn Changed\n");
    list();
}