ASD assignment

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

#define MAX_REGISTRATION_LENGTH 10
#define MAX_MAKE_MODEL_LENGTH 50
#define MAX_COLOR_LENGTH 20

// Define the structure for a car
typedef struct Car {
    char registration[MAX_REGISTRATION_LENGTH];
    char make_model[MAX_MAKE_MODEL_LENGTH];
    char color[MAX_COLOR_LENGTH];
    int prev_owners;
    bool reserved;
    float reserve_amount;
    struct Car *next;
} Car;

// Define the car showroom
typedef struct {
    Car *head;
} CarShowroom;

// Function prototypes
Car *create_car(const char *registration, const char *make_model, const char *color, int prev_owners, bool reserved, float reserve_amount);
void add_car(CarShowroom *showroom, Car *car);
void sell_car(CarShowroom *showroom, const char *registration);
void reserve_car(CarShowroom *showroom, const char *registration, float reserve_amount);
void unreserve_car(CarShowroom *showroom, const char *registration);
void view_all_cars(const CarShowroom *showroom);
void view_car(const CarShowroom *showroom, const char *registration);
void save_to_file(const CarShowroom *showroom);
void load_from_file(CarShowroom *showroom);

int main() {
    CarShowroom showroom;
    showroom.head = NULL;

    load_from_file(&showroom);

    int choice;
    char registration[MAX_REGISTRATION_LENGTH];
    float reserve_amount;
    
    while (true) {
        printf("\nProgram Menu:\n");
        printf("1. Add a new car to the showroom\n");
        printf("2. Sell a car from the showroom\n");
        printf("3. Reserve/Unreserve a car in the showroom\n");
        printf("4. View all cars in the showroom\n");
        printf("5. View a specific car in the showroom\n");
        printf("6. This should be an appropriate option that you provide\n");
        printf("7. Exit the system\n");

        printf("Enter your choice: ");
        scanf("%d", &choice);
        getchar(); 

        switch (choice) {
            case 1:
                // Add a new car
                {
                    char make_model[MAX_MAKE_MODEL_LENGTH];
                    char color[MAX_COLOR_LENGTH];
                    int prev_owners;

                    printf("Enter car registration: ");
                    scanf("%s", registration);
                    getchar(); // Consume newline

                    printf("Enter car make and model: ");
                    fgets(make_model, MAX_MAKE_MODEL_LENGTH, stdin);
                    make_model[strcspn(make_model, "\n")] = 0; 

                    printf("Enter car color: ");
                    fgets(color, MAX_COLOR_LENGTH, stdin);
                    color[strcspn(color, "\n")] = 0; 

                    printf("Enter number of previous owners: ");
                    scanf("%d", &prev_owners);

                    Car *car = create_car(registration, make_model, color, prev_owners, false, 0);
                    add_car(&showroom, car);
                    printf("Car added successfully.\n");
                }
                break;
            case 2:
                // Sell a car
                printf("Enter registration of car to sell: ");
                scanf("%s", registration);
                getchar(); 
                sell_car(&showroom, registration);
                break;
            case 3:
                // Reserve/Unreserve a car
                printf("Enter registration of car to reserve/unreserve: ");
                scanf("%s", registration);
                getchar(); 

                view_car(&showroom, registration);
                printf("Enter reserve amount: ");
                scanf("%f", &reserve_amount);
                getchar(); 

                if (reserve_amount > 0) {
                    reserve_car(&showroom, registration, reserve_amount);
                    printf("Car reserved successfully.\n");
                } else {
                    unreserve_car(&showroom, registration);
                    printf("Car unreserved successfully.\n");
                }
                break;
            case 4:
                // View all cars
                view_all_cars(&showroom);
                break;
            case 5:
                // View a specific car
                printf("Enter registration of car to view: ");
                scanf("%s", registration);
                getchar(); 
                view_car(&showroom, registration);
                break;
            case 6:
                // Placeholder for additional functionality
                printf("This is a placeholder option for additional functionality.\n");
                break;
            case 7:
                // Exit the system
                save_to_file(&showroom);
                printf("Exiting the system.\n");
                exit(0);
            default:
                printf("Invalid choice. Please enter a number between 1 and 7.\n");
        }
    }

    return 0;
}

Car *create_car(const char *registration, const char *make_model, const char *color, int prev_owners, bool reserved, float reserve_amount) {
    Car *car = (Car *)malloc(sizeof(Car));
    strcpy(car->registration, registration);
    strcpy(car->make_model, make_model);
    strcpy(car->color, color);
    car->prev_owners = prev_owners;
    car->reserved = reserved;
    car->reserve_amount = reserve_amount;
    car->next = NULL;
    return car;
}

void add_car(CarShowroom *showroom, Car *car) {
    if (showroom->head == NULL) {
        showroom->head = car;
    } else {
        Car *last_car = showroom->head;
        while (last_car->next != NULL) {
            last_car = last_car->next;
        }
        last_car->next = car;
    }
}

void sell_car(CarShowroom *showroom, const char *registration) {
    if (showroom->head == NULL) {
        printf("Car not found.\n");
        return;
    }

    if (strcmp(showroom->head->registration, registration) == 0) {
        Car *temp = showroom->head;
        showroom->head = showroom->head->next;
        free(temp);
        printf("Car sold successfully.\n");
        return;
    }

    Car *prev_car = showroom->head;
    Car *car = showroom->head->next;
    while (car != NULL) {
        if (strcmp(car->registration, registration) == 0) {
            prev_car->next = car->next;
            free(car);
            printf("Car sold successfully.\n");
            return;
        }
        prev_car = car;
        car = car->next;
    }
    printf("Car not found.\n");
}

void reserve_car(CarShowroom *showroom, const char *registration, float reserve_amount) {
    Car *car = showroom->head;
    while (car != NULL) {
        if (strcmp(car->registration, registration) == 0) {
            car->reserved = true;
            car->reserve_amount = reserve_amount;
            return;
        }
        car = car->next;
    }
}

void unreserve_car(CarShowroom *showroom, const char *registration) {
    Car *car = showroom